Math 100A
Systems of Linear Equations III
Name:
1. Find two numbers with sum 17 and difference 12.
2. Find A so that Ax + 4y = 12 is perpendicular to 4x + y = 3.
3. If two non vertical lines have the same x-intercept, but different y-intercepts, can they be
parallel? Explain your answer.
Math 100A
Systems of Linear Equations III
4. Jonathan and Samantha row their canoe 26 miles downstream in 2 hours. After a picnic,
they row back upstream. After 3 hours they only travel 9 miles. Assuming that they canoe
at a constant rate and the river’s current is constant, find the speed at which Jonathan and
Samantha can row in still water.
5. Suppose that Kristin ate one cheese Runza and drank one medium Pepsi, for a total of 790
calories. Kristin’s friend, Jack, ate two cheese Runzas and drank 1.5 medium Pepsis for a total
of 1475 calories. How many calories are in a cheese Runza? How many calories are in a medium
Pepsi?
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