4.9t^2-10t-87=0

Solution for 4.9t^2-10t-87=0 equation:

4.9t^2-10t-87=0

a = 4.9; b = -10; c = -87;
Δ = b2-4ac
Δ = -102-4·4.9·(-87)
Δ = 1805.2
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{-(-10)-\sqrt{1805.2}}{2*4.9}=\frac{10-\sqrt{1805.2}}{9.8}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+\sqrt{1805.2}}{2*4.9}=\frac{10+\sqrt{1805.2}}{9.8}
$