5x^2+5x=2100

Solution for 5x^2+5x=2100 equation:

5x^2+5x=2100

We move all terms to the left:

5x^2+5x-(2100)=0

a = 5; b = 5; c = -2100;
Δ = b2-4ac
Δ = 52-4·5·(-2100)
Δ = 42025
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{42025}=205$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(5)-205}{2*5}=\frac{-210}{10}
=-21
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(5)+205}{2*5}=\frac{200}{10}
=20
$