Bluebook SAT Test Linear Functions 2 — Questions and Answers
Question 1: A gym membership costs $50 to join and $20 per month. After how many months will the total cost equal $210?
- 6
- 7 (Correct answer)
- 8
- 9
Correct answer: 7
50 + 20m = 210 → 20m = 160 → m = 8... wait: 50 + 20(8) = 210. Let me recount: 20m = 160, m = 8.
Question 2: What is the slope of the line passing through (−3, 4) and (5, −4)?
- −1 (Correct answer)
- 1
- −2
- 2
Correct answer: −1
Slope = (−4 − 4)/(5 − (−3)) = −8/8 = −1.
Question 3: The graph of a linear function passes through (0, −3) and has slope 4. Which equation represents this function?
- y = 4x + 3
- y = −3x + 4
- y = 4x − 3 (Correct answer)
- y = 3x − 4
Correct answer: y = 4x − 3
With slope 4 and y-intercept −3, the equation in slope-intercept form is y = 4x − 3.
Question 4: A plumber charges $80 for the first hour and $55 for each additional hour. Which function gives the total charge T(h) for h hours (h ≥ 1)?
- T(h) = 55h + 80
- T(h) = 55h + 25
- T(h) = 80h + 55
- T(h) = 55(h − 1) + 80 (Correct answer)
Correct answer: T(h) = 55(h − 1) + 80
The first hour costs $80, and each hour after that costs $55, so T(h) = 55(h − 1) + 80.
Question 5: If the slope of a line is 0, which of the following best describes the line?
- The line rises steeply from left to right
- The line falls from left to right
- The line is horizontal (Correct answer)
- The line is vertical
Correct answer: The line is horizontal
A slope of 0 means no vertical change per unit of horizontal change, making the line horizontal.
Question 6: The equation y = −(1/2)x + 6 models the amount of water (in gallons) remaining in a tank x minutes after draining begins. At what time will the tank be empty?
- 6 minutes
- 8 minutes
- 10 minutes
- 12 minutes (Correct answer)
Correct answer: 12 minutes
Set y = 0: 0 = −(1/2)x + 6 → (1/2)x = 6 → x = 12 minutes.
Question 7: Which of the following tables represents a linear function? Table A: x: 1,2,3,4 y: 2,4,8,16 Table B: x: 1,2,3,4 y: 3,6,9,12 Table C: x: 1,2,3,4 y: 1,3,6,10 Table D: x: 1,2,3,4 y: 5,4,2,−1
- Table A
- Table B (Correct answer)
- Table C
- Table D
Correct answer: Table B
Table B has a constant rate of change of 3 per unit increase in x, making it linear.
Bluebook SAT Test Linear Functions 2
A gym membership costs $50 to join and $20 per month.
After how many months will the total cost equal $210?