8x^2+25x-100=0

Solution for 8x^2+25x-100=0 equation:

8x^2+25x-100=0

a = 8; b = 25; c = -100;
Δ = b2-4ac
Δ = 252-4·8·(-100)
Δ = 3825
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:

$\sqrt{\Delta}=\sqrt{3825}=\sqrt{225*17}=\sqrt{225}*\sqrt{17}=15\sqrt{17}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(25)-15\sqrt{17}}{2*8}=\frac{-25-15\sqrt{17}}{16}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(25)+15\sqrt{17}}{2*8}=\frac{-25+15\sqrt{17}}{16}
$