Question

@D3xt3R
I need your help :)

Answer 1

Now we have two function, f(x) and g(x), let's write them\[f(x)=ax+b\\g(x)=mx+n\]If\[(f\cdot g)=f[g(x)]=a*g(x)+b\]\[f[g(x)]=a*(mx+n)+b\]\[f[g(x)]=a*m*x+a*n+b=x\]Now we have \[a*n+b=0\\a*m*x=x\]therefore\[b=-a*n=-\frac{n}{m}\\a=\frac{1}{m}\]replacing\[f(x)=\frac{1}{m}x-\frac{n}{m}\\g(x)=mx-n\]Let's looking for the options that we have. Let's try m=3 and b=2\[f(x)=\frac{1}{3}x-\frac{2}{3}\\g(x)=3x+2\]Your alternatives are wrong\[f(x)=\frac{x-2}{3}\\g(x)=3x+2\] This is the right choise...

Answer 2

Therefore the right answer is C?
@D3xt3R

Answer 3

Yes ;;D