Jika f(x) = x² – 2x dan g(x) = 2x maka

by

(g ⚬ f)(x – 1) =

2x² – 8x + 6
Pembahasan:
f(x) = x² – 2x
g(x) = 2x
(g ⚬ f)(x) = g(f(x))
= g(x² – 2x)
= 2(x² – 2x)
= 2x² – 4x
(g ⚬ f)(x – 1) = 2(x – 1)² – 4(x – 1)
= 2(x² – 2x + 1) – 4x + 4
= 2x² – 4x + 2 – 4x + 4
= 2x² – 8x + 6
  Himpunan penyelesaian dari sistem persamaan 9/x – 4/y = 5 dan 3/x + 1/y = –3 adalah {(x,y)}