(3+7x)(6x+2x)=0

Solution for (3+7x)(6x+2x)=0 equation:

(3+7x)(6x+2x)=0

We add all the numbers together, and all the variables

(7x+3)(+8x)=0

We multiply parentheses ..

(+56x^2+24x)=0

We get rid of parentheses

56x^2+24x=0

a = 56; b = 24; c = 0;
Δ = b2-4ac
Δ = 242-4·56·0
Δ = 576
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{576}=24$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(24)-24}{2*56}=\frac{-48}{112}
=-3/7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(24)+24}{2*56}=\frac{0}{112}
=0
$