Answer:
Length: 21 cm and Width: 6cm
Step-by-step explanation:
Let
be the width and
length of the rectangle. We know:
-------- eq. 1
(Perimeter of the rectangle) ------- eq. 2
Substitute equation 1 in equation 2:

Using the value of y, we find x.

Answer:
a total of 24 presents can be wrapped
Step-by-step explanation:
6 x 3 = 18 feet of ribbon
18 x 12 = 216 inches of ribbon
216/9 = 24 presents can be wrapped
Divide the number of people by the number of plates per pack:
138 / 12 = 11.5
He need to buy 12 packs of plates to have enough.