Question

x^2+5x+2=0 quad formula, is x=6, x=-10?

Answer 1

well does 6^2+5*6+2 = 0?

Answer 2

nope

Answer 3

but in this case is x=6, x=-10

Answer 4

form of our equation
ax^2+bx+c=0
then
\[x=\frac{b\pm\sqrt{b^2-4ac}}{2a}\]
a=1, b = 5, c = 2
so
\[x=\frac{5\pm\sqrt{25-4*1*2}}{2}=\frac{5\pm\sqrt{17}}{2}\]
\[x=\frac{5+\sqrt{17}}{2}\space and \space x=\frac{5-\sqrt{17}}{2} \]