-3.5t^2+210t=0

Solution for -3.5t^2+210t=0 equation:

-3.5t^2+210t=0

a = -3.5; b = 210; c = 0;
Δ = b2-4ac
Δ = 2102-4·(-3.5)·0
Δ = 44100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{44100}=210$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(210)-210}{2*-3.5}=\frac{-420}{-7}
=+60
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(210)+210}{2*-3.5}=\frac{0}{-7}
=0
$