Answer:
0
Step-by-step explanation:
Simplifying
-7(x + -2) + 1 = 15 + -7x
Reorder the terms:
-7(-2 + x) + 1 = 15 + -7x
(-2 * -7 + x * -7) + 1 = 15 + -7x
(14 + -7x) + 1 = 15 + -7x
Reorder the terms:
14 + 1 + -7x = 15 + -7x
Combine like terms: 14 + 1 = 15
15 + -7x = 15 + -7x
Add '-15' to each side of the equation.
15 + -15 + -7x = 15 + -15 + -7x
Combine like terms: 15 + -15 = 0
0 + -7x = 15 + -15 + -7x
-7x = 15 + -15 + -7x
Combine like terms: 15 + -15 = 0
-7x = 0 + -7x
-7x = -7x
Add '7x' to each side of the equation.
-7x + 7x = -7x + 7x
Combine like terms: -7x + 7x = 0
0 = -7x + 7x
Combine like terms: -7x + 7x = 0
0 = 0
Solving
0 = 0
Couldn't find a variable to solve for.
This equation is an identity, all real numbers are solutions.
The point C must be in a line perpendicular tothe x-axis passing through the point B(3,7), then the oordinates of point C must be (3,0)
Answer: Coordinates of point C are (3,0)
Answer:
a) Expected score on the exam is 12.8.
b) Variance 10.24, Standard deviation 3.2
Step-by-step explanation:
For each question, there are only two possible outcomes. Either you guesses the answer correctly, or you does not. The probability of guessing the answer of a question correctly is independent of other questions. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The expected value of the binomial distribution is:

The variance of the binomial distribution is:

The standard deviation of the binomial distribution is:

64 questions.
So 
5 possible answers, one correctly, chosen at random:
So 
(a) What is your expected score on the exam?

(b) Compute the variance and standard deviation of x. Variance =Standard deviation

Variance 10.24

Standard deviation 3.2
.25(4) = 1 gallon
.25(8) = 2 gallons
.25(12) = 3 gallons
.25(16) = 4 gallons
.25(20) = 5 gallons
it would take 20 minutes to remove half the water (aka 5 gallons)
Answer:
x=11
Step-by-step explanation:
Using the Exterior Angle Theorem. . .
(3x+8) + (2x+9) = (8x-16)
Solve to get x = 11