Answer: length is 16m, width is 8m.
Explanation:
It states that the length is 2x the width, which means that l = 2w.
Then, we know that the perimeter is 48, and the perimeter of a rectangle is 2l + 2w, which means our equation is 2l + 2w = 48.
We can substitute 2w for l, or we can substitute l for 2w, but we are keeping the 1st substitution since its faster. Substituting gets us:
2l + l = 48
3l = 48
l = 16
Then, we go back to our equation stating that l = 2w, and plug l in, to get:
16 = 2w
w = 8