2x^2+5x=900

Solution for 2x^2+5x=900 equation:

2x^2+5x=900

We move all terms to the left:

2x^2+5x-(900)=0

a = 2; b = 5; c = -900;
Δ = b2-4ac
Δ = 52-4·2·(-900)
Δ = 7225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{7225}=85$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(5)-85}{2*2}=\frac{-90}{4}
=-22+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(5)+85}{2*2}=\frac{80}{4}
=20
$