Find the mistake in the below maths equations

A = 2
A(A-1) = 2(A-1)
A2-A = 2A-2
A2-2A = A-2
A(A-2) = A-2
A = 1

A shepherd had 18 sheep, out of which, all but ten died.

Can you tell us how many sheep was he left with?

Can you find the hidden animal in the picture below?

I am sure no one can have two things for dinner. what are they?

Why is the Hole below a Lock?

By moving exactly three matchsticks can you make the below equation true.It can be solved by 3 ways.

The current time can be represented by below textual rebus.

0
=========
B.Sc
LLB

Can you tell us the current time?

Replace the question mark with the correct number.

On a charity event in Russia, Murray beat Djokovic by winning six games and losing three games.
Note: There is a total of 5 service breaks(one who serve lost the game).
Who served first, Djokovic or Murray?

Andrew’s doctor gives him three pills and tells him to take one every half hour. How much time will have passed by the time Andrew’s taken all three pills?