A stick l feet long is broken into two parts, one of which is twice as long as the other. How long is the shorter piece?

Well, you really need to think on this one. The shorter piece can be four inches long. See, when you multiply four by two, you get eight. And when you add four and eight together, you get twelve inches, which is one foot.

The stick is L feet long

the2 pieces aer x and y

x=2y

x+y=L

sub 2y for x

2y+y=L

3y=L

divide by 3

y=L/3

the shorter piece is L/3 feet long if the original stick is L feet long