X2+10x=30

Solution for X2+10x=30 equation:

X2+10X=30

We move all terms to the left:

X2+10X-(30)=0

We add all the numbers together, and all the variables

X^2+10X-30=0

a = 1; b = 10; c = -30;
Δ = b2-4ac
Δ = 102-4·1·(-30)
Δ = 220
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:

$\sqrt{\Delta}=\sqrt{220}=\sqrt{4*55}=\sqrt{4}*\sqrt{55}=2\sqrt{55}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-2\sqrt{55}}{2*1}=\frac{-10-2\sqrt{55}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+2\sqrt{55}}{2*1}=\frac{-10+2\sqrt{55}}{2}
$