X*X+25x=300

Solution for X*X+25x=300 equation:

X*X+25X=300

We move all terms to the left:

X*X+25X-(300)=0

We add all the numbers together, and all the variables

25X+X*X-300=0

Wy multiply elements

X^2+25X-300=0

a = 1; b = 25; c = -300;
Δ = b2-4ac
Δ = 252-4·1·(-300)
Δ = 1825
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:

$\sqrt{\Delta}=\sqrt{1825}=\sqrt{25*73}=\sqrt{25}*\sqrt{73}=5\sqrt{73}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(25)-5\sqrt{73}}{2*1}=\frac{-25-5\sqrt{73}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(25)+5\sqrt{73}}{2*1}=\frac{-25+5\sqrt{73}}{2}
$