Question

Using the formula, find the value of $x$ in $x^2+7x+12=0$.

Answer 1

The formula to find the value of x in quadratic equation $(a{x}^2+bx+c)$ is given by

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

Using the same formula we find the value of $x$ in $x^2+7x+12$.

Here, $a=1,b=7,c=12$

$\therefore$ $x=\frac{-7\pm \sqrt{7^2-4\times 1\times 12}}{2\times 1}$

$⟹$ $x=\frac{-7\pm \sqrt{49-48}}{2}$

$⟹$ $x=\frac{-7\pm 1}{2}$

$\therefore$ $x=\frac{-7+1}{2}=-3orx=\frac{-7-1}{2}=-4$

$\therefore$ $x=-3orx=-4$