x(10x+40)=600

Solution for x(10x+40)=600 equation:

X(10X+40)=600

We move all terms to the left:

X(10X+40)-(600)=0

We multiply parentheses

10X^2+40X-600=0

a = 10; b = 40; c = -600;
Δ = b2-4ac
Δ = 402-4·10·(-600)
Δ = 25600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{25600}=160$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(40)-160}{2*10}=\frac{-200}{20}
=-10
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(40)+160}{2*10}=\frac{120}{20}
=6
$