Diketahui f(x) = 4x - 8. jika f(a) = -20, maka nilai a adalah... Mohon bantu yah ka

f(a) = 4.a - 8 =-20
4a = -12
a = -12/4 = -3

f (a) =
4a - 8 = -20
4a = -20+8
4a = -12
a = -12/4
a = -3

bukti
f (-3) = 4 (-3) - 8
= -12-8
=-20