560=30x+5x^2

Solution for 560=30x+5x^2 equation:

560=30x+5x^2

We move all terms to the left:

560-(30x+5x^2)=0

We get rid of parentheses

-5x^2-30x+560=0

a = -5; b = -30; c = +560;
Δ = b2-4ac
Δ = -302-4·(-5)·560
Δ = 12100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{12100}=110$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-30)-110}{2*-5}=\frac{-80}{-10}
=+8
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-30)+110}{2*-5}=\frac{140}{-10}
=-14
$