4x2=15x+25

Solution for 4x2=15x+25 equation:

4x^2=15x+25

We move all terms to the left:

4x^2-(15x+25)=0

We get rid of parentheses

4x^2-15x-25=0

a = 4; b = -15; c = -25;
Δ = b2-4ac
Δ = -152-4·4·(-25)
Δ = 625
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{625}=25$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-15)-25}{2*4}=\frac{-10}{8}
=-1+1/4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+25}{2*4}=\frac{40}{8}
=5
$