Question

f(x) = 4x -1 e g(x)= 5-3x , para que valor de x se tem f(g(x))= -1​

Answer 1

$f(x)=4x-1$

$g(x)=5-3x$

$f(g(x))=4(5-3x)-1$

$f(g(x))=20-12x-1$

$f(g(x))=19-12x$

$f(g(x))=-1$

$19-12x=-1$

$-12x=-1-19$

$-12x=-20$

$12x=20$

$x=\frac{20}{12}$

$x=\frac{5}{3}$

Teremos $f(g(x))=-1$ quando $x=\frac{5}{3}$