Following are some steps to prove that 2=1 :
Step 1: Let A = B
Step 2: Multiply both sides by A:- A² = AB
Step 3: Subtract B² from both sides:- A² - B² = AB - B²
Step 4: Factorize both sides:- ( A + B )( A - B ) = B ( A - B )
Step 5: Divide both sides by ( A - B ) to obtain A + B = B
Step 6: Since A = B hence B + B = B
Step 7: Simplify to obtain 2B = B
Step 8: Divide both sides by B to obtain 2=1.............hence proved.
Which step in the proof is mathematically wrong?