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

What does below science rebus mean?

Ag Ag Ag
Ag SPOON Ag
Ag Ag Ag

John, Jack and Jill are in a desert. John doesn't like Jill and hence decides to murder him. He poisons the water supply of Jill. Since it is a desert area, Jill must drink or he will die of thirst.

Jack does not know of the actions of John and also decides to murder Jill. To succeed in his ill motives, he removes the water supply of Jill so he dies of thirst.

Jill dies due to thirst. Who murdered Jill?

Can you solve this picture maths equation?

Can you tell a 3D object that has just two surfaces?

Find the value of "?" in the ball picture Riddle below:

Spot what is wrong here in below Picture?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?