y^2-100y-2400=0

Solution for y^2-100y-2400=0 equation:

y^2-100y-2400=0

a = 1; b = -100; c = -2400;
Δ = b2-4ac
Δ = -1002-4·1·(-2400)
Δ = 19600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{19600}=140$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-100)-140}{2*1}=\frac{-40}{2}
=-20
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-100)+140}{2*1}=\frac{240}{2}
=120
$