Soal no. 4 tolong yahh

[tex]\displaystyle f(2x-1)=6x+15\\f(2x-1+1)=6(x+1)+15\\f(2x)=6x+6+15\\f\left(2x\cdot\frac12\right)=6\left(\frac12x\right)+21\\f(x)=3x+21\\\\y=3x+21\\y-21=3x\\\frac{y-21}{3}=x\\\frac13x-7=f^{-1}(x)\\\\g(3x+1)=\frac{2x-1}{3x-5}\\g(3x)=\frac{2x-2-1}{3x-3-5}\\g\left(3x\cdot\frac13\right)=\frac{2\cdot\frac13x-3}{3\cdot\frac13x-8}\\g(x)=\frac{\frac23x-3}{x-8}\\g(x)=\frac{2x-9}{3x-24}\\\\y=\frac{2x-9}{3x-24}\\3xy-24y=2x-9\\3xy-2x=24y-9\\x(3y-2)=24y-9\\x=\frac{24y-9}{3y-2}\\g^{-1}(x)=\frac{24x-9}{3x-2}[/tex]
[tex]\displaystyle g^{-1}(3)=\frac{24(3)-9}{3(3)-2}\\g^{-1}(3)=\frac{72-9}{9-2}\\g^{-1}(3)=\frac{63}{7}\\g^{-1}(3)=9\\\\(f^{-1}\circ g^{-1})(3)=f^{-1}(g^{-1}(3))\\(f^{-1}\circ g^{-1})(3)=f^{-1}(9)\\(f^{-1}\circ g^{-1})(3)=\frac13(9)-7\\(f^{-1}\circ g^{-1})(3)=3-7\\\boxed{\boxed{(f^{-1}\circ g^{-1})(3)=-4}}[/tex]

f(2x-1) = 6x+15
[tex] f^{-1} (6x+15) = 2x-1 [/tex]
g(3x+1) = [tex] \frac{2x-1}{3x-5} [/tex]
[tex]g^{-1} ( \frac{2x-1}{3x-5}) = 3x+1 [/tex]

[tex] \frac{2x-1}{3x-5} = 3[/tex]
[tex]2x-1 = 3(3x-5) [/tex]
[tex]2x-1 = 9x-15 [/tex]
[tex]14 = 7x [/tex]
[tex]2 = x[/tex]

[tex]g^{-1} ( 3 ) = 3(2)+1 [/tex]
[tex]g^{-1} ( 3 ) = 7[/tex]


6x+15 = a
6x= a-15
x= (a-15)/6
[tex] f^{-1} (x) = 2((x-15)/6)-1 [/tex]
[tex] f^{-1} (x) = (x-15)/3-1 [/tex]
[tex] f^{-1} (7) = (7-15)/3-1 [/tex]
[tex] f^{-1} (x) = -8/3-1 [/tex]
[tex] f^{-1} (g^{-1}(3)) = -11/3 [/tex]