Buktikan bahwa invers dari fungsi f(x) = (ax + b) / (cx + d) adalah f⁻¹(x) = (-dx + b) / (cx - a) !

f(x) = (ax + b) / (cx + d)
y =(ax + b) / (cx + d)
y(cx + d) = ax + b
ycx + yd = ax + b
ycx - ax = -yd + b
x(yc - a) = -yd + b
x = -yd + b / yc - a
f-¹(x) = -dx + b / cx - a