Solve by using the quadratic formula $\displaystyle x^2-13x+30=0$
Note,Originally Posted by Brooke
$\displaystyle a=1,b=-13,c=30$
Thus,
$\displaystyle x=\frac{b\pm \sqrt{b^2-4ac} }{2a}$
Thus,
$\displaystyle x=\frac{-13\pm \sqrt{169-4(1)(30)}}{2(1)}$
Thus,
$\displaystyle x=\frac{-13\pm \sqrt{169-120}}{2}$
Thus,
$\displaystyle x=\frac{-13\pm 7}{2}$
Thus,
$\displaystyle x=\frac{-13+7}{2}=-3,x=\frac{-13-7}{2}=-10$