(3+v)(3v+7)=0

Solution for (3+v)(3v+7)=0 equation:

(3+v)(3v+7)=0

We add all the numbers together, and all the variables

(v+3)(3v+7)=0

We multiply parentheses ..

(+3v^2+7v+9v+21)=0

We get rid of parentheses

3v^2+7v+9v+21=0

We add all the numbers together, and all the variables

3v^2+16v+21=0

a = 3; b = 16; c = +21;
Δ = b2-4ac
Δ = 162-4·3·21
Δ = 4
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4}=2$
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(16)-2}{2*3}=\frac{-18}{6}
=-3
$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(16)+2}{2*3}=\frac{-14}{6}
=-2+1/3
$