I'm here to help. Ask as many questions as you like. I'm not afraid of questions.
Basically a function is inverse of the other, if that function can be substituted into the other, and the result be simply x.
For example, say the function is f(x)=2x. and the other function is g(x)=3x-8. When you plug in either equation in place of x, if you simplify it should only be x left.
6x-16 isn't x.
These functions are not inverses of eachother.
But to the one you asked about:
f(x)=1/7x + 2/7
g(x)=7x - 2.
f(g(x))=1/7 (7x - 2) + 2/7
f(g(x))=7/7x - 2/7 + 2/7
So when function g(x) is substituted into f(x), the remaining value is simply x. No we have to plug f(x) into g(x) to see if we just get x.
g(f(x))=7(1/7x + 2/7) -2
7/7x + 14/7 - 2
Which means g(f(x))=x.
These two functions are inverses of eachother.
I know math can be difficult. I have different ways of thinking, so I had a hard time in all my math classes. Math can be difficult, but if you need help in the future, let me know. Email me: firstname.lastname@example.org
Take care partner.
Glad to help. If you need further clarification, let me know.