4x^2-70x+215=0

Solution for 4x^2-70x+215=0 equation:

4x^2-70x+215=0

a = 4; b = -70; c = +215;
Δ = b2-4ac
Δ = -702-4·4·215
Δ = 1460
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:

$\sqrt{\Delta}=\sqrt{1460}=\sqrt{4*365}=\sqrt{4}*\sqrt{365}=2\sqrt{365}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-70)-2\sqrt{365}}{2*4}=\frac{70-2\sqrt{365}}{8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-70)+2\sqrt{365}}{2*4}=\frac{70+2\sqrt{365}}{8}
$