-7000000+500000x+250x^2=0

Solution for -7000000+500000x+250x^2=0 equation:

-7000000+500000x+250x^2=0

a = 250; b = 500000; c = -7000000;
Δ = b2-4ac
Δ = 5000002-4·250·(-7000000)
Δ = 257000000000
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:

$\sqrt{\Delta}=\sqrt{257000000000}=\sqrt{100000000*2570}=\sqrt{100000000}*\sqrt{2570}=10000\sqrt{2570}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(500000)-10000\sqrt{2570}}{2*250}=\frac{-500000-10000\sqrt{2570}}{500}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(500000)+10000\sqrt{2570}}{2*250}=\frac{-500000+10000\sqrt{2570}}{500}
$