2x2=1,8x+7,2

Solution for 2x2=1,8x+7,2 equation:

2x^2=1.8x+7.2

We move all terms to the left:

2x^2-(1.8x+7.2)=0

We get rid of parentheses

2x^2-1.8x-7.2=0

a = 2; b = -1.8; c = -7.2;
Δ = b2-4ac
Δ = -1.82-4·2·(-7.2)
Δ = 60.84
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{-(-1.8)-\sqrt{60.84}}{2*2}=\frac{1.8-\sqrt{60.84}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1.8)+\sqrt{60.84}}{2*2}=\frac{1.8+\sqrt{60.84}}{4}
$