750-5x-4.9x^2=0

Solution for 750-5x-4.9x^2=0 equation:

750-5x-4.9x^2=0

a = -4.9; b = -5; c = +750;
Δ = b2-4ac
Δ = -52-4·(-4.9)·750
Δ = 14725
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{14725}=\sqrt{25*589}=\sqrt{25}*\sqrt{589}=5\sqrt{589}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-5)-5\sqrt{589}}{2*-4.9}=\frac{5-5\sqrt{589}}{-9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5)+5\sqrt{589}}{2*-4.9}=\frac{5+5\sqrt{589}}{-9.8}
$