So we are given a system:

Substitute x = 2 we get the system:

Multiply the first equation by -5 and the second by 2 we get the system:

Adding the two equations we get :

We find the value of y by using any of the other equations like this:

Final solution:
If that was the end and the question was "How many boxes did she sell?" then the answer is 6 boxes.
Answer:
18x^2
Step-by-step explanation:
You're basically just multiplying them together :)
12.8 miles would take the 16 friends to split the trip into 16 parts
Answer:
A is given by:

Step-by-step explanation:
The base length of the triangle is 4 units shorter than the height.
This means that 
So



The expression for A in terms of h only was given above.