Bluebook SAT Test Linear Functions 4

Question 1

The linear function h models the height (in feet) of a balloon t minutes after launch: h(t) = 120 + 15t. What is the height of the balloon after 8 minutes?

Accepted Answer

240 feet

Answer

h(8) = 120 + 15(8) = 120 + 120 = 240 feet.

Question 2

What is the x-intercept of the line with equation 3x + 5y = 15?

Accepted Answer

(5, 0)

Answer

Set y = 0: 3x = 15 → x = 5, so the x-intercept is (5, 0).

Question 3

Two linear functions are defined as f(x) = 2x + 3 and g(x) = 2x − 5. Which of the following is true about their graphs?

Accepted Answer

They are parallel (never intersect)

Answer

Both functions have slope 2 but different y-intercepts, so their graphs are parallel lines that never intersect.

Question 4

A student earns $12.50 per hour working part-time. If the student works h hours and has already saved $75, which function gives the total savings S(h)?

Accepted Answer

S(h) = 12.50h + 75

Answer

The initial savings ($75) is the y-intercept and the hourly rate ($12.50) is the slope: S(h) = 12.50h + 75.

Question 5

Line m has the equation x = −4. Which of the following best describes this line?

Accepted Answer

A vertical line at x = −4

Answer

Equations of the form x = k represent vertical lines passing through (k, 0) on the x-axis.

Bluebook SAT Practice Test

Bluebook SAT Practice Test

Bluebook SAT Test Linear Functions 4