Question

sejam f (x)=3x-a e g(x)=5x+3. encontre o valor de a para que f (g (x)=g (f (x)).

Answer 1

f(5x+3)= 3(5x+3)-a
15x+9-a

g(3x-a)= 5(3x-a)+3
15x-5a+3

15x+9-a=15x-5a+3
15x-15x-a+5a=3-9
4a= -6
a= -6/4
a= -3/2