0,9x^2=7,2x

Solution for 0,9x^2=7,2x equation:

0.9x^2=7.2x

We move all terms to the left:

0.9x^2-(7.2x)=0

We add all the numbers together, and all the variables

0.9x^2-(+7.2x)=0

We get rid of parentheses

0.9x^2-7.2x=0

a = 0.9; b = -7.2; c = 0;
Δ = b2-4ac
Δ = -7.22-4·0.9·0
Δ = 51.84
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{-(-7.2)-\sqrt{51.84}}{2*0.9}=\frac{7.2-\sqrt{51.84}}{1.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-7.2)+\sqrt{51.84}}{2*0.9}=\frac{7.2+\sqrt{51.84}}{1.8}
$