1250000=-5p^2+15000p

Solution for 1250000=-5p^2+15000p equation:

1250000=-5p^2+15000p

We move all terms to the left:

1250000-(-5p^2+15000p)=0

We get rid of parentheses

5p^2-15000p+1250000=0

a = 5; b = -15000; c = +1250000;
Δ = b2-4ac
Δ = -150002-4·5·1250000
Δ = 200000000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{200000000}=\sqrt{100000000*2}=\sqrt{100000000}*\sqrt{2}=10000\sqrt{2}$
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-15000)-10000\sqrt{2}}{2*5}=\frac{15000-10000\sqrt{2}}{10}
$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15000)+10000\sqrt{2}}{2*5}=\frac{15000+10000\sqrt{2}}{10}
$