Linear Functions Flashcards
7 cards from real Bluebook SAT Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Linear Functions flashcards as text
A line with equation y = kx − 4 passes through the point (3, 8). What is the value of k?
Answer: 4
Substitute (3, 8): 8 = 3k − 4 → 3k = 12 → k = 4.
The rate of change of a linear function is 5 and f(2) = 11. What is f(0)?
Answer: 1
f(x) = 5x + b; 11 = 5(2) + b → b = 1, so f(0) = 1.
Line p is parallel to the line y = 3x − 7 and passes through (1, 2). What is the equation of line p?
Answer: y = 3x − 1
Parallel lines have equal slopes; using slope 3 and point (1, 2): 2 = 3(1) + b → b = −1, so y = 3x − 1.
A cell phone plan charges a monthly base fee of $25 plus $0.10 per text message. If a customer's bill is $37, how many text messages did they send?
Answer: 120
25 + 0.10t = 37 → 0.10t = 12 → t = 120 text messages.
The graph below has a y-intercept of 4 and passes through (2, 0). What is the slope of the line?
Answer: −2
Slope = (0 − 4)/(2 − 0) = −4/2 = −2.
If f is a linear function and f(−1) = 7 and f(3) = −1, what is f(1)?
Answer: 3
Slope = (−1 − 7)/(3 − (−1)) = −8/4 = −2; using f(−1) = 7: 7 = −2(−1) + b → b = 5; f(1) = −2(1) + 5 = 3.
In the equation y = 2x + c, the line passes through the origin. What is the value of c?
Answer: 0
Passing through the origin means (0, 0) is on the line; 0 = 2(0) + c → c = 0.