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

Find the next number in the sequence

5 12 24 36 ?

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Can you calculate the amount of money the owner spent if there were 3552 employees?

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2, 3, 5, 9, 17, _ What is the next number in the sequence?

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