First, we draw a diagram that represents the situation to help us see what is happening.

We are asked to find her speed walking and riding her bike. Let’s call her walking speed r. Since her biking speed is three miles per hour faster, we will call that speed r+3. We write the speeds in the chart.
The speed is in miles per hour, so we need to express the times in hours, too, in order for the units to be the same. Remember, 1 hour is 60 minutes. So:
30 minutes is6030or21hour15 minutes is6015or41hour
We write the times in the chart.
Next, we multiply rate times time to fill in the distance column.

The equation will come from the fact that the distance from Naoko’s home to her school is the same whether she is walking or riding her bike.
So we say:
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| Translate to an equation. |
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| Solve this equation. |
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| Clear the fractions by multiplying by the LCD of all the fractions in the equation. |
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| Simplify. |
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| Let’s check if this works. Walk 3 mph (0.5 hour)Bike 6 mph (0.25 hour)==1.5miles1.5miles |
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Yes, either way Naoko travels 1.5 miles to school.
Naoko’s walking speed is 3 mph and her speed riding her bike is 6 mph.