Answer:

Step-by-step explanation:
Let
denotes number of pencils, markers, erasers respectively.
For Andrea:

For Justin:

For Virginia:

On subtracting equations (i) and (ii), we get

Put
in equation (i)

Put
in equation (iii)

Multiply equation (iv) by 5 and equation (v) by 6 and then subtract both the equations.

Put
in equation 

Put
in equation (i)

I needed help with that too
There are two answers:
B) 5
C) 8
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Explanation:
If we had a triangle with sides a, b and c, then we can say
b-a < c < b+a
where b is larger than 'a'. This is the triangle inequality theorem
In this case, a = 5 and b = 9 so,
b-a < c < b+a
9-5 < c < 9+5
4 < c < 14
Telling us that c is some number between 4 and 14, not including either endpoint. If c is a whole number, then c could be any value from this set: {5,6,7,8,9,10,11,12,13}
We see that the numbers 5 and 8 are in this set. The values 3 and 15 are not in the set.
Answer:
30 1/10
Step by step explanation:
71/2-5 2/5= 30 1/10
30 1/10 divided by a (also know as 1) = 30 1/10