X(x-3)=700

Solution for X(x-3)=700 equation:

X(X-3)=700

We move all terms to the left:

X(X-3)-(700)=0

We multiply parentheses

X^2-3X-700=0

a = 1; b = -3; c = -700;
Δ = b2-4ac
Δ = -32-4·1·(-700)
Δ = 2809
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2809}=53$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-3)-53}{2*1}=\frac{-50}{2}
=-25
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3)+53}{2*1}=\frac{56}{2}
=28
$