Tolong dibantu pakai caranya ya kak

Tolong dibantu pakai caranya ya kak

$f(x + 1) = frac{2x - 1}{x + 5}$

misal : x + 1 = R

x = R – 1

$f(r) = frac{2(r - 1) - 1}{(r - 1) + 5} \ = frac{2r - 2 - 1}{r + 4} \ = frac{2r - 3}{r + 4} \ f(x) = frac{2x - 3}{x + 4}$