Dicari dulu f(x)nya Lalu Substitusi x=-2
f(x) = (2x-3) / (4x+1) , x ≠ -¼
misalkan f(x) = y, maka
y = (2x-3) / (4x+1)
y(4x+1) = 2x-3
4xy+y = 2x-3
4xy-2x = -y-3
x(4y-2) = -y-3
x = -y-3 / (4y-2)
f-¹(x) = (-x-3) / (4x-2)
f-¹(-2) = (2-3) / (-8-2)
f-¹(-2) = -1 / -10
f-¹(-2) = 1/10 (E)