3x(x+1.5)=180

Solution for 3x(x+1.5)=180 equation:

3x(x+1.5)=180

We move all terms to the left:

3x(x+1.5)-(180)=0

We multiply parentheses

3x^2+4.5x-180=0

a = 3; b = 4.5; c = -180;
Δ = b2-4ac
Δ = 4.52-4·3·(-180)
Δ = 2180.25
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{-(4.5)-\sqrt{2180.25}}{2*3}=\frac{-4.5-\sqrt{2180.25}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4.5)+\sqrt{2180.25}}{2*3}=\frac{-4.5+\sqrt{2180.25}}{6}
$