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7-77.

Pierre was walking toward school at a rate of two miles per hour. He started six miles from school. Dom left school and walked toward Pierre at a rate of four miles per hour. When and how far from school will the boys pass each other? Homework Help ✎

Drawing a picture may be helpful.

Try and write an expression to represent these actions.

Notice that Pierre and Dom must walk a combined total of 6 miles.

To find the amount of miles one person walks, you must multiply the rate by the time.
Let x represent the amount of time the two will have walked when they pass each other.

Since the two must walk a total of 6 miles:

At 1 hour, how many miles will Pierre have walked?
How far will he be from school?

2x + 4x = 6
Solve.

x = 1 hour