(x+5)(x-5)=3x

Solution for (x+5)(x-5)=3x equation:

(x+5)(x-5)=3x

We move all terms to the left:

(x+5)(x-5)-(3x)=0

We add all the numbers together, and all the variables

-3x+(x+5)(x-5)=0

We use the square of the difference formula

x^2-3x-25=0

a = 1; b = -3; c = -25;
Δ = b2-4ac
Δ = -32-4·1·(-25)
Δ = 109
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{-(-3)-\sqrt{109}}{2*1}=\frac{3-\sqrt{109}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3)+\sqrt{109}}{2*1}=\frac{3+\sqrt{109}}{2}
$