Question

A piece of yarn 29 inches long is cut into two parts. If one of the resulting pieces is M inches long represents the length of the other piece

Answer 1

15 inches and 14 inches.

Explanation:

Answer 2

29-M

Explanation:

First, remember that in algebra you represent quantities by means of letters, and because that you can use he usual operations between quantities as well as letters. For example you can write
`x+y` in algebra because
`x` and
`y` are viewed as quantities. Also you can say
`z-5` because
`z` and 5 are both quantities.

Suppose that you have a yarn 29 inches long and is cut into two parts, and one of the pars is 10 inghes long (just suppose it). then the other part must be 19 inches long. What is the operation that you used? ... is a substraction! that is, you did the operation 29-10=19.

Now, if one of the resulting piece is M inches long, the other one must be

`29-M`

inches long, because you must do a substraction like in the above example.