Question

Solve the given quadratic equation by factorization
$8x^2-22x-21=0$

Answer 1

Given : $8x^2-22x-21=0$
$\Rightarrow 8x^2-28x+6x-21=0$

$\Rightarrow 4x(2x-7)+3(2x-7)=0\Rightarrow (2x-7)(4x+3)=0$

$\Rightarrow 2x-7=0or4x+3=0$
$\Rightarrow x=\frac{7}{2}orx=-\frac{3}{4}$
thus, $x=\frac{7}{2}$ and $x=-\frac{3}{4}$ are the two roots of the given equation.