Question

Solve the quadratic equation $2x^2+5x+2=0$

Answer 1

The given quadratic equation is $2x^2+5x+2=0$

On comparing with $a{x}^2+bx+c=0$
We get, $a=2,b=5,c=2$

$D=b^2-4ac$

$={\left(5\right)}^2-4\times 2\times 2$
$=25-16$
$=9$

$x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$

$=\frac{-5\pm \sqrt{9}}{2\times 2}=\frac{-5\pm 3}{4}$

$x=\frac{-5+3}{4}$ or

$x=\frac{-5-3}{4}$

$⟹x=-\frac{1}{2}$ or $x=-2$
$\therefore$ $-\frac{1}{2}$ and $-2$ are the roots of given quadratic equation.