Question

Solve the equation: $3+\frac{30}{x^2}=-\frac{21}{x}$

• A. $x=2,5$
• B. $x=-2,5$
• C. $x=-2,-5$
• D. $x=2,-5$

Answer 1

The correct option is C $x=-2,-5$

Solve the equation as follows:

$3+\frac{30}{x^2}=-\frac{21}{x}$

$\Rightarrow \frac{30}{x^2}+\frac{21}{x}+3=0$

$\Rightarrow 30+21x+3x^2=0$

$\Rightarrow x^2+7x+10=0$

Finding the roots of the above equation as:

$\Rightarrow x^2+5x+2x+10=0$

$\Rightarrow x(x+5)+2(x+5)=0$

$\Rightarrow x+2=0$ and $x+5=0$

$\Rightarrow x=-2$ and $x=-5$