Question

Diketahui rumus fungsi f(x) = ax + b. Jika f(-2) = 2 dan f(3) = -8, nilai f(7) adalah......
A. -21
B. -18
C. -16
D. 8
E. 12

Answer 1

F(x)=ax+b
f(-2) = -2a+b = 2
f(3) = 3a+b = -8
eliminasi b diperoleh : -5a = 10
a=-2 maka b = -2
f(x)= -2x-2
f(7) = -2(7) - 2= -14 -2 = -16