4(x^2+70x-50)=0

Solution for 4(x^2+70x-50)=0 equation:

4(x^2+70x-50)=0

We multiply parentheses

4x^2+280x-200=0

a = 4; b = 280; c = -200;
Δ = b2-4ac
Δ = 2802-4·4·(-200)
Δ = 81600
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:

$\sqrt{\Delta}=\sqrt{81600}=\sqrt{1600*51}=\sqrt{1600}*\sqrt{51}=40\sqrt{51}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(280)-40\sqrt{51}}{2*4}=\frac{-280-40\sqrt{51}}{8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(280)+40\sqrt{51}}{2*4}=\frac{-280+40\sqrt{51}}{8}
$