Answer:
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Explanation:
The given statement: Wangari plants trees at a constant rate of 12 trees every 3 hours.
Using unitary method, the number of tree planted by Wangari in every hour :

i.e. Wangari plants trees at a constant rate of 4 trees every hour.
Let the number of trees planted by Wangari be 'p'and h, the time she spends planting them in hours.
Then, equation that relates p and h will be:
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