You subtract the biggest number from the smallest number...
21-13=8
To solve this problem you must apply the proccedure shown below:
1. The formula for calculate the perimeter of a rectangle is:

Where
is the length and
is the width.
2. The length is
more than the width, therefore:

3. Substitute values into the formula for calculate the perimeter and solve for the width:

3. Then, the length is:

The answer is: The length is
and the width is 
The sum of their ages equals 80.
Gabrielle is 3 times older than Mikhail
Two numbers that have a sum of 80, with one number being 3 times the other are:
Gabrielle’s age: 60
Mikhail’s age: 20
60 + 20 = 80
20 x 3 = 60
Mikhail is 20 years old.
Answer:
3.6
Step-by-step explanation:
divide 36 by 10 be sure it's the easiest part
Answer:
50.4
Step-by-step explanation:
38.12 + 12.24 = 50.36
6 is near 10
50.36 = 50.4