math

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farmer fred had chickens and cows on his farm. he knows that together there are 108 legs and 30 heads. how many of each type of animal does he have?

• math -

c chickens have 2c legs
m cows have 4m legs

c+m = 30
2c + 4m = 108

multiply the top equation by two, and subtract

2c + 2m = 60
2c + 4m = 108

2m = 48
m = 24
c = 6

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