Question

Se f(x) = 2x + 3, qual o valor de x para f(x) = 8?​

Answer 1

$Se~~f(x)=8~,~~temos:\\\\\\f(x)~=~2x~+~3\\\\\\8~=~2x~+~3\\\\\\2x~=~8-3\\\\\\2x~=~5\\\\\\\boxed{x~=~\frac{5}{2}~~ou~~2,5}$