3x^2+30x=55

Solution for 3x^2+30x=55 equation:

3x^2+30x=55

We move all terms to the left:

3x^2+30x-(55)=0

a = 3; b = 30; c = -55;
Δ = b2-4ac
Δ = 302-4·3·(-55)
Δ = 1560
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:

$\sqrt{\Delta}=\sqrt{1560}=\sqrt{4*390}=\sqrt{4}*\sqrt{390}=2\sqrt{390}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(30)-2\sqrt{390}}{2*3}=\frac{-30-2\sqrt{390}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(30)+2\sqrt{390}}{2*3}=\frac{-30+2\sqrt{390}}{6}
$