a = b
a^2 = ab; multiplied by a
a^2 - b^2 = ab - b^2; subtracted b^2
(a-B) * (a+B) = b * (a-B); a^2 - b^2 is differance of two squares, factored b from right side
a + b = b; devided by (a-B)
a + a = a; substituted a for b
2a = a; combined the a's
2 =1; plugged in 1 for a

There are no errors in math on this page, only an error in logic.

What is the error in logic?