First, let's turn all the numbers into improper fractions so that we can find the answer easier.
-2
= r - 
-
= r - 
Now we have to isolate 'r'.
First, we have to make sure that the variable is on one side and all the numbers are on the other side.
To do this, we have to add
to both sides.
In order to do this, we need to ensure that both fractions have a common denominator.
-
= r - 
Ensure that the denominators are the same:
= r - 
+
= r
= r
Good luck!
x^2 = 800. Take the square root of each side.
x = √(800) and -√(800)
Answer:
See Explanation
Step-by-step explanation:
Given

Required
Determine the number of cans for the wall
The dimension of the wall is not given. So, I will use the following assumed values:


First, calculate the area of the wall



If 
Then 
Cross Multiply:



Make x the subject


400 cans using the assume dimensions.
So, all you need to to is, get the original values and follow the same steps
Answer:
The answer is 3.
Explanation:
Factors of 18:
1, 2, 3, 6, 9, 18.
Factors of 21:
1, 3, 7.
The highest number that both sets contain is 3, so the GCF will be 3.
I think it would be $14 per book