Question

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

Answer 1

$$\begin{gathered} =x=\frac{-b\pm \sqrt{b^2-4ac}}{2a} \\ here,a=1,b=7,c=12 \\ =x=\frac{-7\pm \sqrt{7^2-4\times 1\times 12}}{2\times 1} \\ =x=\frac{-7\pm \sqrt{49-48}}{2} \\ =x=\frac{-7\pm 1}{2} \end{gathered}$$

$$\begin{gathered} x=\frac{-7+1}{2}=-3orx=\frac{-7-1}{2}=-4 \\ x=-3orx=-4 \end{gathered}$$