2.5x^2=1.8

Solution for 2.5x^2=1.8 equation:

2.5x^2=1.8

We move all terms to the left:

2.5x^2-(1.8)=0

We add all the numbers together, and all the variables

2.5x^2-1.8=0

a = 2.5; b = 0; c = -1.8;
Δ = b2-4ac
Δ = 02-4·2.5·(-1.8)
Δ = 18
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{18}=\sqrt{9*2}=\sqrt{9}*\sqrt{2}=3\sqrt{2}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-3\sqrt{2}}{2*2.5}=\frac{0-3\sqrt{2}}{5}
=-\frac{3\sqrt{2}}{5}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+3\sqrt{2}}{2*2.5}=\frac{0+3\sqrt{2}}{5}
=\frac{3\sqrt{2}}{5}
$