0.3x(x-5)=0.4-0.2x

Solution for 0.3x(x-5)=0.4-0.2x equation:

0.3x(x-5)=0.4-0.2x

We move all terms to the left:

0.3x(x-5)-(0.4-0.2x)=0

We add all the numbers together, and all the variables

0.3x(x-5)-(-0.2x+0.4)=0

We multiply parentheses

0x^2+0x-(-0.2x+0.4)=0

We get rid of parentheses

0x^2+0x+0.2x-0.4=0

We add all the numbers together, and all the variables

x^2+1.2x-0.4=0

a = 1; b = 1.2; c = -0.4;
Δ = b2-4ac
Δ = 1.22-4·1·(-0.4)
Δ = 3.04
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{-(1.2)-\sqrt{3.04}}{2*1}=\frac{-1.2-\sqrt{3.04}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1.2)+\sqrt{3.04}}{2*1}=\frac{-1.2+\sqrt{3.04}}{2}
$