4.9t^2-12.0t-70=0

Solution for 4.9t^2-12.0t-70=0 equation:

4.9t^2-12.0t-70=0

We add all the numbers together, and all the variables

4.9t^2-12t-70=0

a = 4.9; b = -12; c = -70;
Δ = b2-4ac
Δ = -122-4·4.9·(-70)
Δ = 1516
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1516}=\sqrt{4*379}=\sqrt{4}*\sqrt{379}=2\sqrt{379}$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-12)-2\sqrt{379}}{2*4.9}=\frac{12-2\sqrt{379}}{9.8}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12)+2\sqrt{379}}{2*4.9}=\frac{12+2\sqrt{379}}{9.8}
$