400t-5t^2=0

Solution for 400t-5t^2=0 equation:

400t-5t^2=0

a = -5; b = 400; c = 0;
Δ = b2-4ac
Δ = 4002-4·(-5)·0
Δ = 160000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{160000}=400$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(400)-400}{2*-5}=\frac{-800}{-10}
=+80
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(400)+400}{2*-5}=\frac{0}{-10}
=0
$