Question

Dada a função f: ℝ→ ℝ, definida pela lei f(x) = 5x -8. Determine o valor de x, para o qual f(x) = -23​

Answer 1

$\boxed{\begin{array}{l}\sf f(x)=5x-8\\\sf f(x)=-23\iff 5x-8=-23\\\sf 5x=8-23\\\sf 5x=-15\\\sf x=-\dfrac{15}{5}\\\\\sf x=-3\end{array}}$