Question

Find the roots of the equation $x^2+7x+12=0$ by using the formula

Answer 1

Solution:

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

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

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

$x=\frac{-7\pm \sqrt{49-48}}{2}$

$x=\frac{-7\pm 1}{2}$

$x=\frac{-7+1}{2}$ or $x=\frac{-7-1}{2}$

$x=-3$ or $x=-4$