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

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

-(3u+2)(u+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^2-23u-14=0

a = -3; b = -23; c = -14;
Δ = b2-4ac
Δ = -232-4·(-3)·(-14)
Δ = 361
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{361}=19$
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-23)-19}{2*-3}=\frac{4}{-6}
=-2/3
$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-23)+19}{2*-3}=\frac{42}{-6}
=-7
$