# How do you solve 4.2m+4=2.5?

Mar 25, 2015

Except for attempting to divide by zero, you can perform the same basic arithmetic operation to both sizes on an equation and the equation remains valid.

Starting with
$4.2 m + 4 = 2.5$

Subtract $4$ from both sides of the equation:
$4.2 m = - 1.5$

Divide both sides by $4.2$
$m = - \frac{5}{14} = - 0.3571 \ldots$