1. To find the length of the edge, you will divide the total distance of 36 cm between the 4 edges that are shown.
36/4 = 9 cm per edge.
2. To find the surface area, find the area of one square (9 cm x 9 cm = 81 square cm), and multiply it by 6.
81 square cm x 6 = 486 square cm
486 square cm is the surface area.
Let x be the number of cases of paper towels and y be the number of cases of soap. The system of linear equation that would best represent the given is,
x + y = 10
12x + 15y = 129
The values of x and y are 7 and 3.
Sarah both 7 cases of paper towel.
It is not possible for Sarah to buy exactly 20 bottles because first of all the cases contains only 12 bottles and 20 is not divisible by 12.
Answer: D is the correct answer.
