1200=(700-100p)p

Solution for 1200=(700-100p)p equation:

1200=(700-100p)p

We move all terms to the left:

1200-((700-100p)p)=0

We add all the numbers together, and all the variables

-((-100p+700)p)+1200=0


We calculate terms in parentheses: -((-100p+700)p), so:

(-100p+700)p

We multiply parentheses

-100p^2+700p

Back to the equation:

-(-100p^2+700p)


We get rid of parentheses

100p^2-700p+1200=0

a = 100; b = -700; c = +1200;
Δ = b2-4ac
Δ = -7002-4·100·1200
Δ = 10000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{10000}=100$
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-700)-100}{2*100}=\frac{600}{200}
=3
$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-700)+100}{2*100}=\frac{800}{200}
=4
$