Jika f(x( = 1/x+2 , f^-1 invers f, maka f^-1(x) = -4 , x sama dengan?

jawab

f(x)= 1/(x+1)
f⁻¹ {1/(x+1)} = x
f⁻¹ (-4)= ...
1/(x+1) = - 4
-4(x + 1) = 1
-4x - 4 = 1
-4x = 5
x  = -5/4
f⁻¹(- 4) = - 5/4