.14t^2-2t-4.8=0

Solution for .14t^2-2t-4.8=0 equation:

.14t^2-2t-4.8=0

a = .14; b = -2; c = -4.8;
Δ = b2-4ac
Δ = -22-4·.14·(-4.8)
Δ = 6.688
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{-(-2)-\sqrt{6.688}}{2*.14}=\frac{2-\sqrt{6.688}}{0.28}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+\sqrt{6.688}}{2*.14}=\frac{2+\sqrt{6.688}}{0.28}
$