Proof that 2=1
1) . Given.
2) . Multiply both sides by a.
3) . Subtract
from both sides.
4) . Factor both sides.
5) . Divide both sides by
6) . Substitute
for
.
7) . Addition.
8) . Divide both sides by
.
Wait, What?
The error is dividing by (a-b). (a-b) is 0, so this proof divides by 0. Dividing by 0 is illegal. Thus, this proof is false.