2x^2=40x+7000

Solution for 2x^2=40x+7000 equation:

2x^2=40x+7000

We move all terms to the left:

2x^2-(40x+7000)=0

We get rid of parentheses

2x^2-40x-7000=0

a = 2; b = -40; c = -7000;
Δ = b2-4ac
Δ = -402-4·2·(-7000)
Δ = 57600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{57600}=240$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-40)-240}{2*2}=\frac{-200}{4}
=-50
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-40)+240}{2*2}=\frac{280}{4}
=70
$