5t^2=60-20t

Solution for 5t^2=60-20t equation:

5t^2=60-20t

We move all terms to the left:

5t^2-(60-20t)=0

We add all the numbers together, and all the variables

5t^2-(-20t+60)=0

We get rid of parentheses

5t^2+20t-60=0

a = 5; b = 20; c = -60;
Δ = b2-4ac
Δ = 202-4·5·(-60)
Δ = 1600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1600}=40$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-40}{2*5}=\frac{-60}{10}
=-6
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+40}{2*5}=\frac{20}{10}
=2
$