Rocky ate 42 cups of dog food. Since there are 7 days in a week, 21 cups were eaten per week (3x7). Since the question is asking for the amount in two weeks, you multiply 21x2 to get 42.
Answer:

Step-by-step explanation:
<u>Complete the square</u>
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Answer:
(2,-10)
Step-by-step explanation:
I used a graphing tool to graph the system of equations. The the two lines intercept at the point (2,-10). So, (2,-10) is the solution.