Question

Solve the following linear equation.
$\frac{n}{2}-\frac{3n}{4}+\frac{5n}{6}=21$

Answer 1

$\frac{n}{2}-\frac{3n}{4}+\frac{5n}{6}=21$
$\Rightarrow \frac{6n-9n+10n}{12}=21$
$\Rightarrow \frac{7n}{12}=21$
$\Rightarrow n=\frac{21\times 12}{7}$
$\Rightarrow n=36$

To check:
$\frac{n}{2}-\frac{3n}{4}+\frac{5n}{6}=21$
$\Rightarrow \frac{36}{2}-\frac{3\times 36}{4}+\frac{5\times 36}{6}=21$
$\Rightarrow 18-27+30=21$
$\Rightarrow 21=21$
$\Rightarrow LHS.=R.H.S$
Therefore, it is correct.