How do you solve m/8=(m+7)/9?

Apr 27, 2018

$m = 56$

Explanation:

$\text{one way is to use "color(blue)"cross-multiplication}$

•color(white)(x)a/b=c/drArrad=bc

$\Rightarrow 9 m = 8 \left(m + 7\right) \leftarrow \textcolor{b l u e}{\text{distribute}}$

$\Rightarrow 9 m = 8 m + 56$

$\text{subtract "8m" from both sides}$

$9 m - 8 m = \cancel{8 m} \cancel{- 8 m} + 56$

$\Rightarrow m = 56$

$\textcolor{b l u e}{\text{As a check}}$

Substitute this value into the equation and if both sides are equal then it is the solution.

$\text{left } = \frac{56}{8} = 7$

$\text{right } = \frac{56 + 7}{9} = \frac{63}{9} = 7$

$\Rightarrow m = 56 \text{ is the solution}$