2.4x-0.3x^2-2.1=0

Solution for 2.4x-0.3x^2-2.1=0 equation:

2.4x-0.3x^2-2.1=0

a = -0.3; b = 2.4; c = -2.1;
Δ = b2-4ac
Δ = 2.42-4·(-0.3)·(-2.1)
Δ = 3.24
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{-(2.4)-\sqrt{3.24}}{2*-0.3}=\frac{-2.4-\sqrt{3.24}}{-0.6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2.4)+\sqrt{3.24}}{2*-0.3}=\frac{-2.4+\sqrt{3.24}}{-0.6}
$