Question

x/5+x/5=21 determine a raiz de cada equação

Answer 1

$\dfrac{x}{5} + \dfrac{x}{5} =21\to ~~mmc=5\\\\\\ x+x=105\to \\\\ 2x=105\to \\\\ \boxed{x= \frac{105}{2} ~~ou~~x=52,5}$