Question

$2m + 5m = 21$

Explanation:

Step1: Combine like terms

$2m + 5m = 7m$, so the equation becomes $7m = 21$

Step2: Isolate the variable $m$

Divide both sides by 7: $\frac{7m}{7} = \frac{21}{7}$

Answer:

$m = 3$