Question

x^2+2x-15=0 solve by using the quadratic equation

Answer 1

try factoring. it should work in this case

Answer 2

could you show me how to use the quadratic on an equation like this, i know the answer by factoring but need help with the quadratic

Answer 3

yeah here's the answer:
quadratic equation:


plug in 2 as b; 1 as 4;15 as c.
what you should get is \[-2\pm \sqrt{4+60}\]/ 2(1)
\[(-2\pm \sqrt{64})/ 2 \]

this becomes \[(-2\pm8)/2\]
(-2+8)/ 2 = 3 and (-2-8)/2 = -5