X2+30x-300=0

Solution for X2+30x-300=0 equation:

X2+30X-300=0

We add all the numbers together, and all the variables

X^2+30X-300=0

a = 1; b = 30; c = -300;
Δ = b2-4ac
Δ = 302-4·1·(-300)
Δ = 2100
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:

$\sqrt{\Delta}=\sqrt{2100}=\sqrt{100*21}=\sqrt{100}*\sqrt{21}=10\sqrt{21}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(30)-10\sqrt{21}}{2*1}=\frac{-30-10\sqrt{21}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(30)+10\sqrt{21}}{2*1}=\frac{-30+10\sqrt{21}}{2}
$