-2.7t^2+30t-11.5=0

Solution for -2.7t^2+30t-11.5=0 equation:

-2.7t^2+30t-11.5=0

a = -2.7; b = 30; c = -11.5;
Δ = b2-4ac
Δ = 302-4·(-2.7)·(-11.5)
Δ = 775.8
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{-(30)-\sqrt{775.8}}{2*-2.7}=\frac{-30-\sqrt{775.8}}{-5.4}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(30)+\sqrt{775.8}}{2*-2.7}=\frac{-30+\sqrt{775.8}}{-5.4}
$