X2-140x+2400=0

Solution for X2-140x+2400=0 equation:

X2-140X+2400=0

We add all the numbers together, and all the variables

X^2-140X+2400=0

a = 1; b = -140; c = +2400;
Δ = b2-4ac
Δ = -1402-4·1·2400
Δ = 10000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{10000}=100$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-140)-100}{2*1}=\frac{40}{2}
=20
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-140)+100}{2*1}=\frac{240}{2}
=120
$