t(21.65-5t)=0

Solution for t(21.65-5t)=0 equation:

t(21.65-5t)=0

We add all the numbers together, and all the variables

t(-5t+21.65)=0

We multiply parentheses

-5t^2+21.65t=0

a = -5; b = 21.65; c = 0;
Δ = b2-4ac
Δ = 21.652-4·(-5)·0
Δ = 468.7225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(21.65)-\sqrt{468.7225}}{2*-5}=\frac{-21.65-\sqrt{468.7225}}{-10}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(21.65)+\sqrt{468.7225}}{2*-5}=\frac{-21.65+\sqrt{468.7225}}{-10}
$