Question

Solve $\frac{2}{3}(n+6)-\frac{1}{5}(n-4)=\frac{3}{7}(n+12)$, then $n=$.

• A. $-9$
• B. $8$
• C. $3\frac{1}{9}$
• D. $9$

Answer 1

The correct option is D $9$

We need to solve: $\frac{2}{3}(n+6)-\frac{1}{5}(n-4)=\frac{3}{7}(n+12)$

Multiplying by $105$ on both sides, we get

$70(n+6)-21(n-4)=45(n+12)$

$\Rightarrow 70n+420-21n+84=45n+540$

$\Rightarrow 4n=36$

$\Rightarrow n=9$