Diketahui fungsi f(x)=2x-5 dan g(x)=3-x nilai a yang memenuhi (f o g) (a) =7 adalah​

(fog)(x) = f(g(x))

(fog)(x) = f(3-x)

(fog)(x) = 2(3-x)-5

(fog)(x) = 6-2x-5

(fog)(x) = -2x+1

(fog)(a) = -2a+1

7 = -2a+1

2a = 1-7

2a = -6

a = -6/2

a = -3