Answer:
1. A, because 4(2)=8. 2 is the x.
2. B, because 2.5 x 4 = 10, which makes sense.
3. B, because 5x is the amount that you want to put into equal parts and the 3 is just being subtracted from the amount of the equal parts from the 5x.
4. C.
Step-by-step explanation:
Answer:
The answer is C because they have the same coefficient and variable on both sides (or something like that but its definitely c )
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)
