tolong di jawab ya! pliis... pakai jalannya juga..

12. f(x) = 2x-7
f(4) = 2.4-7 = 1 (a)
13. f(x) = -3x+2
f(-2) = -3.-2+2 = 8 (d)
14. f(x) = 3/4x+1
f(8) = 3/4.8+1 = 7 (d)
15. f(x) = x²-12
f(4) = 4²-12= 4 (c)
Nb : ( . ) berarti kali

Semoga membantu☺