tentukan invers f(×)=6×-9÷×+5

y = (6x-9)/(x+5)
y(x+5) = 6x-9
xy+5y = 6x-9
xy-6x = - 5y-9
x(y-6) = - 5y-9
x = (- 5y-9)/(y-6)
f⁻¹(x) = (-5x-9)/(x-6)

Rumus cepat
f(x) = (ax+b)/(cx+d)
f⁻¹(x) = (-dx+b)/(cx-a)

Mapel : Matematika
Kelas : X SMA
Bab : Fungsi Invers

Rumus Cepat :
f(x) = (ax + b)/(cx + d)
f¯¹(x) = (-dx + b)(cx - a)

Pembahasan :
f(x) = (6x - 9)/(x + 5)
f¯¹(x) = (-5x - 9)/(x - 6)
f¯¹(x) = [-(5x + 9)/-(6 - x)]
f¯¹(x) = (5x + 9)/(6 - x)