(5u-4)(2-u)=0

Solution for (5u-4)(2-u)=0 equation:

(5u-4)(2-u)=0

We add all the numbers together, and all the variables

(5u-4)(-1u+2)=0

We multiply parentheses ..

(-5u^2+10u+4u-8)=0

We get rid of parentheses

-5u^2+10u+4u-8=0

We add all the numbers together, and all the variables

-5u^2+14u-8=0

a = -5; b = 14; c = -8;
Δ = b2-4ac
Δ = 142-4·(-5)·(-8)
Δ = 36
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{36}=6$
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(14)-6}{2*-5}=\frac{-20}{-10}
=+2
$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(14)+6}{2*-5}=\frac{-8}{-10}
=4/5
$