5x(x+2)=700

Solution for 5x(x+2)=700 equation:

5x(x+2)=700

We move all terms to the left:

5x(x+2)-(700)=0

We multiply parentheses

5x^2+10x-700=0

a = 5; b = 10; c = -700;
Δ = b2-4ac
Δ = 102-4·5·(-700)
Δ = 14100
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:

$\sqrt{\Delta}=\sqrt{14100}=\sqrt{100*141}=\sqrt{100}*\sqrt{141}=10\sqrt{141}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-10\sqrt{141}}{2*5}=\frac{-10-10\sqrt{141}}{10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+10\sqrt{141}}{2*5}=\frac{-10+10\sqrt{141}}{10}
$