4.5x^2-21x+20=0

Solution for 4.5x^2-21x+20=0 equation:

4.5x^2-21x+20=0

a = 4.5; b = -21; c = +20;
Δ = b2-4ac
Δ = -212-4·4.5·20
Δ = 81
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{81}=9$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-21)-9}{2*4.5}=\frac{12}{9}
=1+1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-21)+9}{2*4.5}=\frac{30}{9}
=3+1/3
$