0=-0.11t^2+4t+7.2

Solution for 0=-0.11t^2+4t+7.2 equation:

0=-0.11t^2+4t+7.2

We move all terms to the left:

0-(-0.11t^2+4t+7.2)=0

We add all the numbers together, and all the variables

-(-0.11t^2+4t+7.2)=0

We get rid of parentheses

0.11t^2-4t-7.2=0

a = 0.11; b = -4; c = -7.2;
Δ = b2-4ac
Δ = -42-4·0.11·(-7.2)
Δ = 19.168
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{-(-4)-\sqrt{19.168}}{2*0.11}=\frac{4-\sqrt{19.168}}{0.22}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4)+\sqrt{19.168}}{2*0.11}=\frac{4+\sqrt{19.168}}{0.22}
$