5x^2+25x-18.75=0

Solution for 5x^2+25x-18.75=0 equation:

5x^2+25x-18.75=0

a = 5; b = 25; c = -18.75;
Δ = b2-4ac
Δ = 252-4·5·(-18.75)
Δ = 1000
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:

$\sqrt{\Delta}=\sqrt{1000}=\sqrt{100*10}=\sqrt{100}*\sqrt{10}=10\sqrt{10}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(25)-10\sqrt{10}}{2*5}=\frac{-25-10\sqrt{10}}{10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(25)+10\sqrt{10}}{2*5}=\frac{-25+10\sqrt{10}}{10}
$