-(-3u-2)(-u+7)=0

Solution for -(-3u-2)(-u+7)=0 equation:

-(-3u-2)(-u+7)=0

We add all the numbers together, and all the variables

-(-3u-2)(-1u+7)=0

We multiply parentheses ..

-(+3u^2-21u+2u-14)=0

We get rid of parentheses

-3u^2+21u-2u+14=0

We add all the numbers together, and all the variables

-3u^2+19u+14=0

a = -3; b = 19; c = +14;
Δ = b2-4ac
Δ = 192-4·(-3)·14
Δ = 529
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{529}=23$
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(19)-23}{2*-3}=\frac{-42}{-6}
=+7
$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(19)+23}{2*-3}=\frac{4}{-6}
=-2/3
$