diketahui g(x)=2-5x dan g(a)=22.nilai a adlah

Kelas 8 Matematika
Bab Fungsi 

g(x) = 2 - 5x

g(a) = 22
2 - 5a = 22
-5a = 22 - 2
a = 20/-5
a = -4

22 = 2 - 5x
22-2 = -5x
20 = -5 x
x= 20/-5
x= -4

maka nilai a = -4