Given parameters:
Equation:
(x-4)²=9
Problem, solve the equation by factoring and extracting the root
Solution:
Given equation:
(x-4)²=9
subtract 9 from both sides to equate to zero;
(x-4)² - 9 = 0
(x -4)² - 3² = 0
Now, this is similar to the concept of difference of two squares;
x² - y² = (x + y)(x-y)
Here x = x-4 and y = -3
So input and solve;
(x - 4 -3)(x - 4 -(-3)) = 0
(x - 7)(x - 4+3) = 0
(x -7)(x -1) = 0
S0,
x - 7 = 0 or x-1 = 0
x = 7 or 1
If we extract the square roots;
(x-4)² = 9
√(x-4)² = √9
x - 4 = 3
x = 4 + 3 = 7; this is not the only solution to the problem
So we cannot solve it by extracting the square root.
The solutions by checking are incorrect for the second solution, hence the expression cannot be solved by extracting the square root. The equation can only be solved by factoring
Given the expression;
(x-4)²=9
This expression can be solved by factoring
Factoring the expression on the left hand side
(x-4)(x-4)=9
x²-4x-4x+16 = 9
x² - 8x + 16 - 9 = 0
x² - 8x + 7 = 0
x² -x - 7x + 7 = 0
x(x-1) -7(x-1) = 0
x-7 = 0 and x - 1 = 0
x = 7 and 1
This shows that the expression can be solved by factoring
The other way is by squaring both sides
(√x-4)² = ±√9
x - 4 =±√9
x = -9+4 and x = 9 + 4
x = -5 and 13
Since the solutions by checking are incorrect for the second solution, hence the expression cannot be solved by extracting the square root
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A flywheel is attached to a crankshaft by 12 bolts, numbered 1 through 12. Each bolt is checked to determine whether it is torqued correctly. Let A be the event that all the bolts are torqued correctly, let B be the event that the #3 bolt is not torqued correctly, let C be the event that exactly one bolt is not torqued correctly, and let D be the event that bolts #5 and #8 are torqued correctly. State whether each of the following pairs of events is mutually exclusive.a. A and Bb. B and Dc. C and Dd. B and C
Answer:
a
Mutually exclusive
b
Not Mutually exclusive
c
Not Mutually exclusive
d
Not Mutually exclusive
Step-by-step explanation:
From the question we are told that
The number of bolt is n = 12
The event that all the bolt are torqued correctly is A
The event that the 3rd bolt is not torqued correctly is B
The event that exactly one bolt is not torqued correctly is C
The event that the [tex]4^{th}[/tex] and [tex]8^{th}[/tex] are torqued correctly is D
Generally for an event to be mutually exclusive it means that both event can not occur at the same time
Considering a
The A and B are mutually exclusive because they can not occur at the same time
Considering b
The event B and D are not mutually exclusive because they can occur at the same time
Considering c
Event C and D are not mutually exclusive because they can occur at the same time
Considering d
Event B and C are not mutually exclusive because they can occur at the same time
find the derivate of : y = ln(x)/5x
y'=
g A population is infected with a certain infectious disease. It is known that 95% of the population has not contracted the disease. A test for this disease is 98% accurate (i.e., a person who has contracted the disease tests positive 98% of the time) and has a 1% false negative rate (i.e., a person without the disease has 1% positive rate). Find the probability that a random selected person from does not have the infection if he or she has tested positive. Briefly explain why you are or are not surprised by your result.
Answer:
There is approximately 17% chance of a person not having a disease if he or she has tested positive.
Step-by-step explanation:
Denote the events as follows:
D = a person has contracted the disease.
+ = a person tests positive
- = a person tests negative
The information provided is:
[tex]P(D^{c})=0.95\\P(+|D) = 0.98\\P(+|D^{c})=0.01[/tex]
Compute the missing probabilities as follows:
[tex]P(D) = 1- P(D^{c})=1-0.95=0.05\\\\P(-|D)=1-P(+|D)=1-0.98=0.02\\\\P(-|D^{c})=1-P(+|D^{c})=1-0.01=0.99[/tex]
The Bayes' theorem states that the conditional probability of an event, say A provided that another event B has already occurred is:
[tex]P(A|B)=\frac{P(B|A)P(A)}{P(B|A)P(A)+P(B|A^{c})P(A^{c})}[/tex]
Compute the probability that a random selected person does not have the infection if he or she has tested positive as follows:
[tex]P(D^{c}|+)=\frac{P(+|D^{c})P(D^{c})}{P(+|D^{c})P(D^{c})+P(+|D)P(D)}[/tex]
[tex]=\frac{(0.01\times 0.95)}{(0.01\times 0.95)+(0.98\times 0.05)}\\\\=\frac{0.0095}{0.0095+0.0475}\\\\=0.1666667\\\\\approx 0.1667[/tex]
So, there is approximately 17% chance of a person not having a disease if he or she has tested positive.
As the false negative rate of the test is 1%, this probability is not unusual considering the huge number of test done.
Simplify the expression: (4x2 - 3x + 1) - (3x2 - 5x + 4)
Answer:
x² + 2x - 3
Step-by-step explanation:
Step 1: Write expression
(4x² - 3x + 1) - (3x² - 5x + 4)
Step 2: Distribute negative
4x² - 3x + 1 - 3x² + 5x - 4
Step 3: Combine like terms (x²)
x² - 3x + 1 + 5x - 4
Step 4: Combine like terms (x)
x² + 2x + 1 - 4
Step 5: Combine like terms (constants)
x² + 2x - 3
Which equation matches the graph?
Answer:
equation C
Step-by-step explanation:
y-axis = 4
gradient of line is -2/3
PLEASE HELP 50 PTS
For a function j(x), the difference quotient is 3x2 + 3xh + h2. What is the average rate of change of j(x) over the interval [–1, 6]?
15
21
25
31
Answer:
31 is correct guys
Step-by-step explanation:
Since the data is incomplete, for the given question the required average rate of change is given by 15 + 3h.
Given that,
For a function j(x), the difference quotient is 3x2 + 3xh + h2.
The average rate of change of j(x) over the interval [–1, 6] is to be determined.
What are functions?Functions is the relationship between sets of values. e g y=f(x), for every value of x there is its exists in a set of y. x is independent while Y is the dependent variable.
Here, the average rate of change = f(6) - f(-1) / (6 + 1)
So,
f(6) = 108 + 18h + h²
f(-1) = 3 - 3h + h²
Now,
average rate of change = [(108 + 18h + h²) - (3 - 3h + h²)]/(7)
= [105 + 21 h ] / 7
= 15 + 3h
Thus, the required average rate of change is given by 15 + 3h.
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HURRY HURRY (function)
Answer:
h
Step-by-step explanation:
3. The average rate of change of the function f(x) on the interval -2 is less than or equal to X which is less than or equal to 4 is -3.5. If f (4)=11 then which
of the following is the value of f(-2)?
(1) -11
(3) 21
(2) -21
(4) 32
The value of the function f(x) at x = - 2 is equivalent to 32.
What is a mathematical function, equation and expression?function : In mathematics, a function from a set X to a set Y assigns to each element of X exactly one element of Y. The set X is called the domain of the function and the set Y is called the codomain of the function.expression : A mathematical expression is made up of terms (constants and variables) separated by mathematical operators.equation : A mathematical equation is used to equate two expressions.Equation modelling is the process of writing a mathematical verbal expression in the form of a mathematical expression for correct analysis and results of the given problemGiven is that the average rate of change of the function f(x) on the interval -2 is less than or equal to [x] which is less than or equal to 4 is -3.5.
In the range of {- 2 ≤ x ≤ 4}, the rate of change of f(x) is -3.5. This means we can write -
r = {f(4) - f(-2)}/(4 + 2)
f(4) = 11 and [r] = - 3.5. So, we can write -
- 3.5 = {11 - f(-2)}/6
11 - f(-2) = -3.5 x 6
11 - f(-2) = - 21
f(-2) = 11 + 21
f(-2) = 32
Therefore, the value of the function f(x) at x = - 2 is equivalent to 32.
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Pls help i dont understand :(
you drink a beverage with 120 mg of caffeine. Each hour, the amount m of caffine in a persons system decreases by 12%. About how much caffeine will be in your system after 3 hours? Round your answer to the nearest milligram
Answer:43.2
Step-by-step explanation: multiply 120 x 0.12 and you get 14.4, since it’s 3 hours multiply 14.4 3 times and u get 43.2
I can't find the right answer
Answer:
x^2 ≥ 4
Step-by-step explanation:
[tex]x^2\ge \:4\\\\\mathrm{For\:}u^n\:\ge \:\:a\\\mathrm{,\:if\:}n\:\mathrm{is\:even}\mathrm{\:then\:}u\:\le \:\:-\sqrt[n]{a}\:or\:u\:\ge \sqrt[n]{a}\\\\x\le \:-\sqrt{4}\quad \mathrm{or}\quad \:x\ge \sqrt{4}\\\\\sqrt{4}=2\\\\x\le \:-2\quad \mathrm{or}\quad \:x\ge \:2[/tex]
Answer:
A
You can take the square root of the inequality x^2<4, which will make it x< plus or minus 2 (x<2, x<-2)
You know it is this answer because, the sign cannot be greater than or equal to since the circles aren't filled, and if you solve the other inequality, the answer you get does not match.
Hope this helps!! :)
A model rocket is launched from the roof of a building. Its flight path is modeled
by h = -5t^2 +30t +10 where h is the height of the rocket above the ground in
metres and r is the time after the launch in seconds.
What is the rocket's maximum height?
Answer:
55
Step-by-step explanation:
This is the equation of a parabola. To make things simpler, we can replace [tex]h[/tex] with [tex]y[/tex] and [tex]t[/tex] with [tex]x[/tex]. Therefore, [tex]y=-5x^2+30x+10[/tex]. Because the coefficient of the [tex]x^2[/tex] term is negative, we know the parabola points down, and the maximum height is the vertex. The x coordinate of the vertex of a parabola can be found with the equation [tex]-\frac{b}{2a}[/tex], or [tex]-\frac{30}{-10} = 3[/tex]. Plugging in [tex]3[/tex] into the equation gives us [tex]y = -5(3)^2+30(3)+10 = \boxed{55}[/tex]
Can someone please help,ty!!
Look where the graph crosses the vertical y axis. This point is the y intercept.
In this case, the y intercept is located at (0, -1)
You start at the origin (0,0) and move down 1 unit to get to (0, -1)
Side note: The equation of this line is y = 2x-1
Which is the most accurate measurement of 1 pound?
Answer:
I would say 15 ounces
Jamal wants to subtract 16-7. First he subtract 16-6 then he subtracts 1 why will he get the correct answer
Step-by-step explanation: He will get the answer correct because if you add the 6 & 1 together it equals Seven. Seven was the original number that was supposed to be subtracted from 16.
Sorry if I didnt help
If Georgina travels 455 km in 7 hours how far will she travel in 9 hours at the same rate
Answer:
585 km
Step-by-step explanation:
rate of speed formula: distance/time
455/7=65
65*9=585
The ratio of girls to boys in a school simplifies to 2:3. How many boys are there if there are 345 students in the school?
Answer:
230
Step-by-step explanation:
You should multiply 345 by 2/3 or you can divide 345 by 3, which equaks 115 and then multiply 115 by 2 which equals 230.
The number of boys in the school is 207.
Given
The ratio of girls to boys in a school simplifies to 2:3.
We need to find out how many boys are there if there are 345 students in the school.
What are ratios?The ratio gives us an idea between two quantities.
It is denoted by a:b
Example:
The ratio of apple and mango in the basket is 1:2.
The total number of fruits is 12.
Apple = [ 1 / (1+2) ] x 12 = (1/3) x 12 = 4
Mango = [ 2/(1+2) ] x 12 = (2/3) x 12 = 2 x 4 = 8
We have,
Total number of students = 345
The ratio of girls to boys = 2:3
The number of boys :
= [ 3 / (2+3) ] x 345
= [ 3/5 ] x 345
= 3 x 69
= 207
Thus the number of boys in the. school is 207.
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Simple equation with division that equals 8
Answer:
64 divided by 8
Step-by-step explanation:
Answer:
16 divided by 2 = 8
Step-by-step explanation:
give the sum of difference 4/9+1/6
Answer:
11/18
Step-by-step explanation:
4/9 + 1/6
Get a common denominator of 18
4/9 * 2/2 = 8/18
1/6 * 3/3 = 3/18
8/18+3/18
11/18
Answer:
11/18
4/9 + 1/6
Get a common denominator of 18
4/9 * 2/2 = 8/18
1/6 * 3/3 = 3/18
8/18+3/18
11/18
ez
Step-by-step explanation:
Tyler then takes his remaining paper and does it again. He cuts the paper to create four equal pieces, then hands one piece each to the others and keeps one for himself. What fraction of the original piece of paper does each person have now?
Answer:
Each person has 1/4 of a peice of paper
Step-by-step explanation: Tyler cut the peices of paper in 4 equal pieces and if he gave himself and another person one peice then they would each of 1/4 of a peice of paper
15 less than a number is equal to 12
Answer:
Step-by-step explanation:
x - 15 = 12
x = 27
Mr. Howard lost money on his investments at a rate of $7 per day. Which expression shows how much money he lost over the course of 5 days?
Answer:
7 x 5 = 35 or the amount lost
Step-by-step explanation:
greatest common factor for 32-4x
Answer:
4
out of
32
−
4
x
.
4
(
8
−
x
)
Step-by-step explanation:
A. What is the experimental (or independent) variable?
b. The consumer variable (whether they normally disclose or not disclose goals ) in the experiment is considered as a _________ variable.
c. What is the dependent variable?
D. Describe one possible main effect?
e. Describe an interaction effect?
F. What is the purpose of random assignment in this experiment. Be specific.
2. Design a test marketing study
John Paul gave the cashier $60 to pay for 8 bags of potatoes. The cashier gave him $24.32 in change. What is the cost in dollars and cents for each bag of potatoes?
Answer:
$4.46
Step-by-step explanation:
$60- 24.32= $35.68
So $35.68=8 bags of potatoes.
Then ÷8 to find 1 bag.
$35.68 ÷8 = $4.46
$4.46=1 BAG
HELP ASAP this is hard
Answer:
C
Step-by-step explanation:
Answer:
D) positive association because the data on the scattergraph is decreasing (y axis) as the x axis increases.
Basically the data: theres a cluster, an outlier and has a negative association. Not a positive association.
A jury pool has 17 men and 24 women, from which 12 jurors will be selected. Assuming that each person is equally likely to be chosen and that the jury is selected at random, find the following probabilities:
Give all answers accurate to six decimal places.
a) all men
b)all women
c) 8 men 4 women
d) 6 men 6 women
Answer:
since [tex]17+24=41[/tex]
a) [tex]\frac{\binom{17}{12}}{\binom{42}{12}}[/tex]
b) [tex]\frac{\binom{24}{12}}{\binom{42}{12}}[/tex]
c) [tex]\frac{\binom{17}{8} \cdot \binom{24}{4}}{\binom{42}{8}\cdot\binom{36}{4}}[/tex]
d) [tex]\frac{\binom{17}{6}\cdot\binom{24}{6}}{\binom{17}{6}\cdot\binom{36}{6}}[/tex]
Just calculate these. If there is anything wrong just let me know.
the number of painted turtles in a pond is one less than half of the number of bullfrogs. Let f represent the number of bullfrogs. Write an expression fro the number of painted turtles
Answer:
X = 1/2f - 1
Step-by-step explanation:
X is how many painted turtles in the pond. This would be the expression that you would you use to find the actual number of turtles, but we are just leaving it at the expression.
7th grade math help me plzzz
Answer:
1. 3>-3
2. 12<24
3. -12>-24
4. 5=-(-5)
5. 7.2>7
6. -7.2<-7
7. -1.5=-3/2
8. -4/5>-5/4
9. -3/5=-6/10
10. -2/3<1/3
Step-by-step explanation:
Convert and round to the nearest HUNDREDTH. 1 cup is about 236.59 mL