10x(x+9)=350

Solution for 10x(x+9)=350 equation:

10x(x+9)=350

We move all terms to the left:

10x(x+9)-(350)=0

We multiply parentheses

10x^2+90x-350=0

a = 10; b = 90; c = -350;
Δ = b2-4ac
Δ = 902-4·10·(-350)
Δ = 22100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{22100}=\sqrt{100*221}=\sqrt{100}*\sqrt{221}=10\sqrt{221}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(90)-10\sqrt{221}}{2*10}=\frac{-90-10\sqrt{221}}{20}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(90)+10\sqrt{221}}{2*10}=\frac{-90+10\sqrt{221}}{20}
$