X^2+9=6x+28

Solution for X^2+9=6x+28 equation:

X^2+9=6X+28

We move all terms to the left:

X^2+9-(6X+28)=0

We get rid of parentheses

X^2-6X-28+9=0

We add all the numbers together, and all the variables

X^2-6X-19=0

a = 1; b = -6; c = -19;
Δ = b2-4ac
Δ = -62-4·1·(-19)
Δ = 112
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:

$\sqrt{\Delta}=\sqrt{112}=\sqrt{16*7}=\sqrt{16}*\sqrt{7}=4\sqrt{7}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-6)-4\sqrt{7}}{2*1}=\frac{6-4\sqrt{7}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-6)+4\sqrt{7}}{2*1}=\frac{6+4\sqrt{7}}{2}
$