The answer is 10...............
If you're asking how much she made per hour, it would be 8.5$
Answer:
B. 
Step-by-step explanation:
GIven that
and
, and that point M is the midpoint of AB, the midpoint can be determined as a vectorial sum of A and B. That is:

The location of B is now determined after algebraic handling:


Then:




Which corresponds to option B.
Simplifying
3x + 4 = 7 + -2x
Reorder the terms:
4 + 3x = 7 + -2x
Solving
4 + 3x = 7 + -2x
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '2x' to each side of the equation.
4 + 3x + 2x = 7 + -2x + 2x
Combine like terms: 3x + 2x = 5x
4 + 5x = 7 + -2x + 2x
Combine like terms: -2x + 2x = 0
4 + 5x = 7 + 0
4 + 5x = 7
Add '-4' to each side of the equation.
4 + -4 + 5x = 7 + -4
Combine like terms: 4 + -4 = 0
0 + 5x = 7 + -4
5x = 7 + -4
Combine like terms: 7 + -4 = 3
5x = 3
Divide each side by '5'.
x = 0.6
Answer: x = 0.6