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

You need to arrange three 7 and mathematical symbols to form number 1?

I am working in a bus company. The company recently went under expansion and therefore there was not enough room for all the buses. As a result, twelve buses had to be stored outside.

If the company decides to expand the garage space by forty percent, enough space to accommodate the current buses will be created leaving enough space for twelve more buses if the need arises in future.

Can you calculate the number of buses that the company owns at present?

'S' refers to the number of seconds in a day and 'H' refers to the number of hours in ten years. Which quantity out of these two is greater?

How do you go from 98 to 720 using just one letter?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

There is a straight highway. Four different villages lie on that highway. The distance between them is different. The third village is 60km away from the first village; the fourth is 40 km away from the second; the third is 10 km near to the fourth that it is to the second.

Can you calculate the distance between the fourth and the first village ?

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I