Let x = 1
Now multiply both sides by x;
x2 = x
Substract 1 from both sides;
x2 – 1 = x – 1
Use the identity x2 – 1 = (x + 1)(x – 1);
(x + 1)(x – 1) = (x – 1)
Cancel the factors (x – 1);
(x + 1) = 1
But x was equal to 1; so
2 = 1
q. e. d.