x+(x-2)+(x^2+x)+(x^2+6)=70

Solution for x+(x-2)+(x^2+x)+(x^2+6)=70 equation:

x+(x-2)+(x^2+x)+(x^2+6)=70

We move all terms to the left:

x+(x-2)+(x^2+x)+(x^2+6)-(70)=0

We get rid of parentheses

x^2+x^2+x+x+x-2+6-70=0

We add all the numbers together, and all the variables

2x^2+3x-66=0

a = 2; b = 3; c = -66;
Δ = b2-4ac
Δ = 32-4·2·(-66)
Δ = 537
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{-(3)-\sqrt{537}}{2*2}=\frac{-3-\sqrt{537}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+\sqrt{537}}{2*2}=\frac{-3+\sqrt{537}}{4}
$