Question

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

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

Answer 1

The correct option is D $9$

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

Multiply $105$ both sides we get

$\frac{2}{3}\times 105(n+6)-\frac{1}{5}\times 105(n-4)=\frac{3}{7}\times 105(n+12)$

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

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

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

$\Rightarrow 4n=36$

$n=9$