Answer:
<h3>
The answer is D.</h3>
Step-by-step explanation:
Explanation:
The rule of a triangle is that it the other two sides could not be longer than longest side of the triangle. If the two sides added up together is greater than the longest side, the triangle would no longer be connected. Since 8 + 12 ft still works for the longest side of the triangle, it will be considered the length of the third side.
Amar's age = a
sister is a - 5
add both = 39
a + (a - 5) = 39
2a - 5 = 39
2a = 44
a = 22 and sister is 17
For this case we have the following system of equations:

To solve, we clear "x" from the second equation:

We substitute "x" in the first equation:

We clear the value of the variable "y":

We look for the value of the variable "x":

Thus, the solution of the system is given by:

Answer:

Option D
Answer:
39 active volcanoes.
Step-by-step explanation:
Subtract 169 (whole) from 130 (part). 9 - 0 = 9, 6 - 3 = 3, and 1 - 1 = 0. Therefore, 169 - 130 = 39
Answer:
C
Step-by-step explanation:
You have to add the whole equation not only a part of it.