0.39(x^2)=5.2x

Solution for 0.39(x^2)=5.2x equation:

0.39(x^2)=5.2x

We move all terms to the left:

0.39(x^2)-(5.2x)=0

We add all the numbers together, and all the variables

0.39x^2-(+5.2x)=0

We get rid of parentheses

0.39x^2-5.2x=0

a = 0.39; b = -5.2; c = 0;
Δ = b2-4ac
Δ = -5.22-4·0.39·0
Δ = 27.04
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{-(-5.2)-\sqrt{27.04}}{2*0.39}=\frac{5.2-\sqrt{27.04}}{0.78}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5.2)+\sqrt{27.04}}{2*0.39}=\frac{5.2+\sqrt{27.04}}{0.78}
$