2b(7b+2)-(7b+2)=0

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

2b(7b+2)-(7b+2)=0

We multiply parentheses

14b^2+4b-(7b+2)=0

We get rid of parentheses

14b^2+4b-7b-2=0

We add all the numbers together, and all the variables

14b^2-3b-2=0

a = 14; b = -3; c = -2;
Δ = b2-4ac
Δ = -32-4·14·(-2)
Δ = 121
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{121}=11$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-3)-11}{2*14}=\frac{-8}{28}
=-2/7
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3)+11}{2*14}=\frac{14}{28}
=1/2
$