0=4x^2-25x-30

Solution for 0=4x^2-25x-30 equation:

0=4x^2-25x-30

We move all terms to the left:

0-(4x^2-25x-30)=0

We add all the numbers together, and all the variables

-(4x^2-25x-30)=0

We get rid of parentheses

-4x^2+25x+30=0

a = -4; b = 25; c = +30;
Δ = b2-4ac
Δ = 252-4·(-4)·30
Δ = 1105
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{-(25)-\sqrt{1105}}{2*-4}=\frac{-25-\sqrt{1105}}{-8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(25)+\sqrt{1105}}{2*-4}=\frac{-25+\sqrt{1105}}{-8}
$