The answer is B because n is equal to the number of notebooks. you can not exceed the amount of money that you have to buy the notebooks
When we solve these equations x= 7.5 and y= 1.5.
B. The total area painted is 864; they must buy two cans of paint.
Step-by-step explanation:
Step 1:
A rectangle's area can be calculated by multiplying its length and its width. The wall is made up of 5 different types of rectangular walls. All walls are 8 feet tall but the length varies.
Step 2:
The area of the 20 feet long wall = 
The area of the 10 feet long wall = 
The area of the 5 feet long wall = 
The area of the 4 feet long wall = 
The area of the 15 feet long wall = 
The area of all the walls = 432 square feet.
Since there are two sides for every wall, total area =
square feet.
Step 3:
If one paint can covers 500 square feet,
the number of cans required to paint 864 square feet =
cans.
so 2 paint cans are needed to paint 864 square feet which is option B.
We can use Law of Cosines to solve for the angle of Z. The solution is shown below:
cos C=(a²+b²-c²)/2ab
cos Z = (yz² + xz² - xy² )/2*yz*xz
cos Z = (20² + 25 - 13²)/2*20*25
cos Z = 856 / 1000
Z=31.13°
The answer is angle 31.13°.