Bluebook SAT Test Linear Functions 13

Question 1

Line n is defined by 3x + 6y = 18. What is the slope of a line perpendicular to n?

Accepted Answer

2

Answer

Rewrite: y = −(1/2)x + 3; slope of n = −1/2; perpendicular slope = 2.

Question 2

A function is linear if and only if it has a constant rate of change. Which of the following tables is linear?
A: x=1,2,3,4; y=2,6,12,20 | B: x=0,2,4,6; y=1,5,9,13 | C: x=1,3,5,7; y=3,9,27,81 | D: x=0,1,2,3; y=4,3,1,−2

Accepted Answer

B

Answer

Table B has a constant rate of change: +4 per +2 units in x (slope = 2). The others have non-constant rates.

Question 3

If f(x) = 4x + b and f(2) = 11, what is f(−1)?

Accepted Answer

−1

Answer

f(2) = 8 + b = 11 → b = 3; f(−1) = −4 + 3 = −1.

Question 4

The graph of a linear function has a slope of 0 and passes through (2, −5). Which is the equation?

Accepted Answer

y = −5

Answer

A slope of 0 means a horizontal line; passing through (2, −5) gives y = −5.

Question 5

A savings account starts with $300 and earns $25 per week. How many weeks w until the account reaches $700?

Accepted Answer

16

Answer

300 + 25w = 700 → 25w = 400 → w = 16.

Bluebook SAT Practice Test

Bluebook SAT Practice Test

Bluebook SAT Test Linear Functions 13