Question

dados f(x)=3x+5e g(x)=2x-3 cauculex para que tenha 
a)f(g(x))=0
b)g(f(x))=1

Answer 1

a)$g(x)=2x-3$ e $f(x)=3x+5$:

$f(g(x))=0\\ f(2x-3)=3(2x-3)+5=0\\ 6x-9+5=0\\ 6x-4=0\\ 6x=4\\ x=\dfrac{4}{6}=\dfrac{2}{3}$

b)$g(f(x))=1\\ g(3x+5)=1\\ 2(3x+5)-3=1\\ 6x+10-3=1\\ 6x+7=1\\ 6x=-6\\ x=-1$