25+13x-4.9x^2=0

Solution for 25+13x-4.9x^2=0 equation:

25+13x-4.9x^2=0

a = -4.9; b = 13; c = +25;
Δ = b2-4ac
Δ = 132-4·(-4.9)·25
Δ = 659
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{-(13)-\sqrt{659}}{2*-4.9}=\frac{-13-\sqrt{659}}{-9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(13)+\sqrt{659}}{2*-4.9}=\frac{-13+\sqrt{659}}{-9.8}
$