Question

Di ketahui f(x)=1/2 x-6. jika f(a)=15 maka tentukan nilai a

Answer 1

F(x) = (x/2)-6
f(a) = (a/2)-6 = 15
          a/2 = 15+6
          a/2 = 21
          a = 21 x 2
          a = 42
 :)

Answer 2

F(x) = 1/2 x-6
f(a) = 1/2 a-6
15 = 1/2 a -6
15+6 = 1/2 a
21 = 1/2 a
21 :1/2 = a
21 × 2 = a
42 = a
maka nilai a = 42