Question 1024709
the whole is equal to the sum of its parts.
the length of the pipe before it was cut has to be x + 76.


you do not know the value of x, nor do you have any way of finding it, short of measuring it.


so you go with what you have.


there are two parts.


one part measures 76 feet.
the other part measures x feet.


the whole pipe has to measure x + 76 feet before it was cut.