(-6+b)(2+7)b=5

Solution for (-6+b)(2+7)b=5 equation:

(-6+b)(2+7)b=5

We move all terms to the left:

(-6+b)(2+7)b-(5)=0

We add all the numbers together, and all the variables

(b-6)9b-5=0

We multiply parentheses

9b^2-54b-5=0

a = 9; b = -54; c = -5;
Δ = b2-4ac
Δ = -542-4·9·(-5)
Δ = 3096
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{3096}=\sqrt{36*86}=\sqrt{36}*\sqrt{86}=6\sqrt{86}$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-54)-6\sqrt{86}}{2*9}=\frac{54-6\sqrt{86}}{18}
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-54)+6\sqrt{86}}{2*9}=\frac{54+6\sqrt{86}}{18}
$