Bantu no 3 & 4 pls jawab

3]
f(x)= (2x - 3)/(4x + 1)
f⁻¹(x)=...?

y= (2x - 3)/(4x + 1)
y(4x + 1)= 2x - 3
4xy + y= 2x - 3
4xy - 2x= -3 - y
x(4y - 2)= -3 - y
x= (-3 - y)/(4y - 2)
f⁻¹(x)= (-3 - x)/(4x - 2)

4]
f(x)= (x + 3)/(6 - x)
f⁻¹(a)= 3

y= (x + 3)/(6 - x)
y(6 - x)= x + 3
6y - xy= x + 3
x + xy= 6y - 3
x(1 + y)= 6y - 3
x= (6y - 3)/(1 + y)
f⁻¹(x)= (6x - 3)/(1 + x)

f⁻¹(a)= 3
(6.a - 3)/(1 + a)= 3
6a - 3= 3(1 + a)
6a - 3= 3 + 3a
6a - 3a= 3 + 3
3a= 6
  a= 2