x.3(2x+2)=x+21*

Solution for x.3(2x+2)=x+21* equation:

x.3(2x+2)=x+21*

We move all terms to the left:

x.3(2x+2)-(x+21*)=0

We add all the numbers together, and all the variables

x.3(2x+2)-(+x)=0

We multiply parentheses

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

We get rid of parentheses

2x^2+2x-x=0

We add all the numbers together, and all the variables

2x^2+x=0

a = 2; b = 1; c = 0;
Δ = b2-4ac
Δ = 12-4·2·0
Δ = 1
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1}=1$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1)-1}{2*2}=\frac{-2}{4}
=-1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+1}{2*2}=\frac{0}{4}
=0
$