Question

Solve the linear equation:

${\displaystyle \frac{n}{2}-\frac{3n}{4}+\frac{5n}{6}=21}$

Answer 1

${\displaystyle \frac{n}{2}-\frac{3n}{4}+\frac{5n}{6}=21}$

${\displaystyle \frac{6n-3\left(3n\right)+2\left(5n\right)}{12}=21}$

${\displaystyle \frac{6n-9n+10n}{12}=21}$

${\displaystyle \frac{6n+n}{12}=21}$

${\displaystyle \frac{7n}{12}=12}$

7n = 21 × 12

${\displaystyle n=\frac{21\times 12}{7}}$

n = 36