x(x+42)=2160

Solution for x(x+42)=2160 equation:

x(x+42)=2160

We move all terms to the left:

x(x+42)-(2160)=0

We multiply parentheses

x^2+42x-2160=0

a = 1; b = 42; c = -2160;
Δ = b2-4ac
Δ = 422-4·1·(-2160)
Δ = 10404
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{10404}=102$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(42)-102}{2*1}=\frac{-144}{2}
=-72
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(42)+102}{2*1}=\frac{60}{2}
=30
$