-4.9x^2+76x+87=0

Solution for -4.9x^2+76x+87=0 equation:

-4.9x^2+76x+87=0

a = -4.9; b = 76; c = +87;
Δ = b2-4ac
Δ = 762-4·(-4.9)·87
Δ = 7481.2
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(76)-\sqrt{7481.2}}{2*-4.9}=\frac{-76-\sqrt{7481.2}}{-9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(76)+\sqrt{7481.2}}{2*-4.9}=\frac{-76+\sqrt{7481.2}}{-9.8}
$