3x(x+0.2)=x+1.4

Solution for 3x(x+0.2)=x+1.4 equation:

3x(x+0.2)=x+1.4

We move all terms to the left:

3x(x+0.2)-(x+1.4)=0

We multiply parentheses

3x^2+0.6x-(x+1.4)=0

We get rid of parentheses

3x^2+0.6x-x-1.4=0

We add all the numbers together, and all the variables

3x^2-0.4x-1.4=0

a = 3; b = -0.4; c = -1.4;
Δ = b2-4ac
Δ = -0.42-4·3·(-1.4)
Δ = 16.96
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{-(-0.4)-\sqrt{16.96}}{2*3}=\frac{0.4-\sqrt{16.96}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-0.4)+\sqrt{16.96}}{2*3}=\frac{0.4+\sqrt{16.96}}{6}
$