0=1.5t-1.2t^2

Solution for 0=1.5t-1.2t^2 equation:

0=1.5t-1.2t^2

We move all terms to the left:

0-(1.5t-1.2t^2)=0

We add all the numbers together, and all the variables

-(1.5t-1.2t^2)=0

We get rid of parentheses

1.2t^2-1.5t=0

a = 1.2; b = -1.5; c = 0;
Δ = b2-4ac
Δ = -1.52-4·1.2·0
Δ = 2.25
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{-(-1.5)-\sqrt{2.25}}{2*1.2}=\frac{1.5-\sqrt{2.25}}{2.4}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1.5)+\sqrt{2.25}}{2*1.2}=\frac{1.5+\sqrt{2.25}}{2.4}
$