(2x+1)(x-1)=210

Solution for (2x+1)(x-1)=210 equation:

(2x+1)(x-1)=210

We move all terms to the left:

(2x+1)(x-1)-(210)=0

We multiply parentheses ..

(+2x^2-2x+x-1)-210=0

We get rid of parentheses

2x^2-2x+x-1-210=0

We add all the numbers together, and all the variables

2x^2-1x-211=0

a = 2; b = -1; c = -211;
Δ = b2-4ac
Δ = -12-4·2·(-211)
Δ = 1689
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-\sqrt{1689}}{2*2}=\frac{1-\sqrt{1689}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+\sqrt{1689}}{2*2}=\frac{1+\sqrt{1689}}{4}
$