Question

Please help with this question!

Ari has been paying attention to the number of calories she burns while exercising. One day she spent 3 hours hiking, and 4 canoeing, and she calculated that she burned 2338 calories. The next day, she hiked for 7 hours and canoed for one hour, and she calculated that she burned 3322 calories. How many calories per hour does Ari burn doing each exercise?

Answer 1

Let the calories / hour for hiking = h
Let the calories / hour for canoeing = c
3h + 4 c = 2338
7h + c = 3322 Multiply this by 4

28h + 4c = 13288 Write the first equation underneath this one.
3h + 4c = 2338 Subtract
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25h = 10950 Divide by 25
h = 10950 / 25
h = 438 calories for each hour hiking.

7h + c = 3322
7*438 + c = 3322
3066 + c = 3322
c = 3322 - 3066
c = 256 calories / hour canoeing.