Question

What is the sum of two solutions of the quadratic equation ax^2+bx+c=0

Answer 1

they are
$\frac{-b+ \sqrt{b^2-4ac} }{2a}$ and $\frac{-b- \sqrt{b^2-4ac} }{2a}$
we can see that we can add them because of the same denomenator and also we can see the square root bits cancel each other out
we are left with

$\frac{-b-b}{2a}= \frac{-2b}{2a}= \frac{-b}{a}$

the sum is -b/a