(5b+3)(5b-3)=25b-9

Solution for (5b+3)(5b-3)=25b-9 equation:

(5b+3)(5b-3)=25b-9

We move all terms to the left:

(5b+3)(5b-3)-(25b-9)=0

We use the square of the difference formula

25b^2-(25b-9)-9=0

We get rid of parentheses

25b^2-25b+9-9=0

We add all the numbers together, and all the variables

25b^2-25b=0

a = 25; b = -25; c = 0;
Δ = b2-4ac
Δ = -252-4·25·0
Δ = 625
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{625}=25$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-25)-25}{2*25}=\frac{0}{50}
=0
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-25)+25}{2*25}=\frac{50}{50}
=1
$