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

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?

Can you start the fire using two pieces of wood?

I am a type of word that is spelt incorrectly or used differently, on purpose for humour. What am I?
Hint 1: You can find me in a joke.
Hint 2: I am a play on words.

Railroad Crossing, look out for the cars. Can you spell that, without any R's ?

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.

I am first found in caves, now prolific online; I am a depiction, a drawing, a symbol, or sign. I will convey whichever mood you could wish; or for that matter, a fist, flask, or fish. What am I?

A Child was born in Lahore, Pakistan.

Still child is not a Pakistani citizen.why ?

Next Number in the Series,

5, 16, 49, 104, ?

Forwards I am heavy, backward I am not. What am I?