What is this maths problem called

The function f,g and h each have the set of real numbers as their domain are defined as follows:
f(x)=7-2x g(x)=4x-1 h(x)=3(x-1)

Find the values of x for which:
f g(x)=-15 g h(x)=11 f f(x)=102



thank you!

Composition of Functions

fog(x)=7-2(4x-1)=7-8x+2=-8x+9

-15=8x+9

-24=8x

x=-3

goh=4(3x-3)-1=12x-12-1=12x-13

11=12x-13

24=12x

x=2

fof=7-2(7-2x)=7-14+4x=-7+4x

102=-7+4x

109=4x

x=109/'