(x)(3x+8)=210

Solution for (x)(3x+8)=210 equation:

(x)(3x+8)=210

We move all terms to the left:

(x)(3x+8)-(210)=0

We multiply parentheses

3x^2+8x-210=0

a = 3; b = 8; c = -210;
Δ = b2-4ac
Δ = 82-4·3·(-210)
Δ = 2584
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:

$\sqrt{\Delta}=\sqrt{2584}=\sqrt{4*646}=\sqrt{4}*\sqrt{646}=2\sqrt{646}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-2\sqrt{646}}{2*3}=\frac{-8-2\sqrt{646}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+2\sqrt{646}}{2*3}=\frac{-8+2\sqrt{646}}{6}
$