Sat practice Test #8 Answer Explanations

Choice C is correct. The graph of an equation given in the form 
y = mx + b has slope m. The equation in choice C is y = 3x + 2, so the 
slope of its graph is 3.
Choices A, B, and D are incorrect. They are all given in the form 
y = mx + b, where m is the slope. Therefore, choice A has a graph with 
a slope of 1 
_ 
3 , choice B has a graph with a slope of 1 (because x = 1 ∙ x), 
and choice D has a graph with a slope of 6.

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ANSwER ExPlANATIONS
| SAT Practice Test #8
QUESTION 8
Choice B is correct. Multiplying both sides of the equation by x + 1 
gives (x + 1)
2
= 2. This means x + 1 is a number whose square is 2, so 
(x + 1) is either
√ 
_
2 or − 
√ 
_
2 . Therefore,
√ 
_
2 is a possible value for x + 1.
Choice A is incorrect and may result from trying to find the value of x 
instead of x + 1 and making a sign error. Choice C is incorrect and may 
result from solving for (x + 1)
2
instead of x + 1. Choice D is incorrect 
and may result from squaring instead of taking the square root to find 
the value of x + 1.
QUESTION 9
Choice D is correct. Using the volume formula V = 7πk 
3
_ 
48 and the given 
information that the volume of the glass is 473 cubic centimeters, the 
value of k can be found as follows:
473 = 7πk 
3
_ 
48
 k 
3
=
473(48)
_
7π 
 k = 
3
√ 
_
473(48)
_
7π ≈ 10.10690
Therefore, the value of k is approximately 10.11 centimeters.
Choices A, B, and C are incorrect. Substituting the values of k from 
these choices in the formula results in volumes of approximately 
7 cubic centimeters, 207 cubic centimeters, and 217 cubic centimeters, 
respectively, all of which contradict the given information that the 
volume of the glass is 473 cubic centimeters.
QUESTION 10