diketahui fungsi f(x) = 10x - 2 dan fungsi f(k) = 18 nilai k adalah

Diketahui
f(x) = 10x - 2
f(k) = 18

Penyelesaian
   f(k) = 10k - 2
    18 = 10k - 2
- 10k = - 18 - 2
- 10k = -20
  10k = 20
       k = 20/10
      k = 2