0.07*(1+2*x)*x=0.18

Solution for 0.07*(1+2*x)*x=0.18 equation:

0.07(1+2x)*x=0.18

We move all terms to the left:

0.07(1+2x)*x-(0.18)=0

We add all the numbers together, and all the variables

0.07(2x+1)*x-(0.18)=0

We add all the numbers together, and all the variables

0.07(2x+1)*x-0.18=0

We multiply parentheses

0x^2+0x-0.18=0

We add all the numbers together, and all the variables

x^2+x-0.18=0

a = 1; b = 1; c = -0.18;
Δ = b2-4ac
Δ = 12-4·1·(-0.18)
Δ = 1.72
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{1.72}}{2*1}=\frac{-1-\sqrt{1.72}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+\sqrt{1.72}}{2*1}=\frac{-1+\sqrt{1.72}}{2}
$