Question

Solve the following quadratic equation by formula method-
$3x^2+8x-3=0$

Answer 1

$3x^2+8x-3=0$
On comparing with general quadratic equation : $a{x}^2+bx+c=0$
We get $a=3,b=8,c=-3$
Formula $x=\frac{-b\pm \sqrt{b^2-4ac}}{2}$
$x=\frac{-8\pm \sqrt{8^2-\mathrm{4.3.}(-3)}}{2.3}$
$x=\frac{-8\pm \sqrt{64+36}}{6}$
$x=\frac{-8\pm \sqrt{100}}{6}$
$x=\frac{-8\pm 10}{6}$
On taking positive sign
$x=\frac{-8+10}{6}$
$x=\frac{2}{6}=\frac{1}{3}$
On taking negative sign
$x=\frac{-8-10}{6}$
$x=\frac{-18}{6}=-3$
Thus, the solution of the equations are
$x=\frac{1}{3},x=-3$.