Question

Please, it's urgent.

I am thinking of a number...
I multiply it by 4 and add 136.
I get the same answer if I multiply by 9 and subtract 9.
What is my number?

Answer 1

Start from a number x.

If you multiply it by 4 you get 4x.

Then, you add 136 to get 4x+136.

On the other hand, if you start with the same number and multiply it by 9, you get 9x.

Subtract 9 and you get 9x-9.

These two procedures get the same result, so we have

`4x+136=9x-9`

Subtract 4x from both sides to get

`136=5x-9`

Add 9 to both sides to get

`145=5x`

Divide both sides by 5 to get

`x=(145)/(5)=29`