X^2+70x+245=0

Solution for X^2+70x+245=0 equation:

X^2+70X+245=0

a = 1; b = 70; c = +245;
Δ = b2-4ac
Δ = 702-4·1·245
Δ = 3920
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:

$\sqrt{\Delta}=\sqrt{3920}=\sqrt{784*5}=\sqrt{784}*\sqrt{5}=28\sqrt{5}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(70)-28\sqrt{5}}{2*1}=\frac{-70-28\sqrt{5}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(70)+28\sqrt{5}}{2*1}=\frac{-70+28\sqrt{5}}{2}
$