(2x+7)(2x-7)=(x+1)(x-1)

Solution for (2x+7)(2x-7)=(x+1)(x-1) equation:

(2x+7)(2x-7)=(x+1)(x-1)

We move all terms to the left:

(2x+7)(2x-7)-((x+1)(x-1))=0

We use the square of the difference formula

4x^2+x^2-49+1=0

We add all the numbers together, and all the variables

5x^2-48=0

a = 5; b = 0; c = -48;
Δ = b2-4ac
Δ = 02-4·5·(-48)
Δ = 960
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{960}=\sqrt{64*15}=\sqrt{64}*\sqrt{15}=8\sqrt{15}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-8\sqrt{15}}{2*5}=\frac{0-8\sqrt{15}}{10}
=-\frac{8\sqrt{15}}{10}
=-\frac{4\sqrt{15}}{5}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+8\sqrt{15}}{2*5}=\frac{0+8\sqrt{15}}{10}
=\frac{8\sqrt{15}}{10}
=\frac{4\sqrt{15}}{5}
$