0=-0.7t^2+35t

Solution for 0=-0.7t^2+35t equation:

0=-0.7t^2+35t

We move all terms to the left:

0-(-0.7t^2+35t)=0

We add all the numbers together, and all the variables

-(-0.7t^2+35t)=0

We get rid of parentheses

0.7t^2-35t=0

a = 0.7; b = -35; c = 0;
Δ = b2-4ac
Δ = -352-4·0.7·0
Δ = 1225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1225}=35$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-35)-35}{2*0.7}=\frac{0}{1.4}
=0
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-35)+35}{2*0.7}=\frac{70}{1.4}
=50
$