Question

If $\frac{35}{x-1}+\frac{35}{x+1}=12,$ then a value of $x$ is:

• A. $6$
• B. $7$
• C. $8$
• D. $5$

Answer 1

The correct option is A $6$

$\frac{35}{x-1}+\frac{35}{x+1}=12$

$\Rightarrow 35x+35+35x-35=12x^2-12$

$\Rightarrow 12x^2-70x-12=0$

$\Rightarrow 6x^2-35x-6=0$

$\Rightarrow 6x^2-36x+x-6=0$

$\Rightarrow 6x(x-6)+1(x-6)=0$

$\Rightarrow (x-6)(6x+1)=0$

$x-6=0\Rightarrow x=6$

$6x+1=0\Rightarrow x=\frac{-1}{6}$