5x-2x^2=-20

Solution for 5x-2x^2=-20 equation:

5x-2x^2=-20

We move all terms to the left:

5x-2x^2-(-20)=0

We add all the numbers together, and all the variables

-2x^2+5x+20=0

a = -2; b = 5; c = +20;
Δ = b2-4ac
Δ = 52-4·(-2)·20
Δ = 185
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(5)-\sqrt{185}}{2*-2}=\frac{-5-\sqrt{185}}{-4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(5)+\sqrt{185}}{2*-2}=\frac{-5+\sqrt{185}}{-4}
$