tolong dibantu ya kak

f(x) = akar (x + 1)
f[g(x)] = 2 akar (x - 1)
g(x)...?

f[g(x)] = 2 akar (x - 1)
akar [g(x) + 1] = 2 akar (x - 1), kuadratkan
g(x) + 1 = 4(x - 1)
g(x) = 4x - 4 - 1
g(x) = 4x - 5