Question

The table represents some points on the graph of linear function f.
x | -2 | 1 | 5 | 10
f(x) | -224 | 64 | 448 | 928


Which function represents f ?

(1 point)

f(x)=−2(32x−3)


f(x)=16(2x−1)


f(x)=−32(x−3)


f(x)=32(3x−1)

Answer 1

Find the slope: between x=1 and x=5, slope = (448−64)/(5−1) = 384/4 = 96.
So f(x) = 96x + b. Using f(1)=64 gives 96 + b = 64 ⇒ b = −32.
Thus f(x) = 96x − 32 = 32(3x − 1).

Answer: f(x) = 32(3x − 1).