You can put this solution on YOUR website! how many birds and lions do you have in your zoo? If there are 30 heads and 100 feet.
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Let # of birds be "b"; let number of lions be "l"
Head equation: b+l = 30
Feet equation: 2b+4l = 100
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l = 30-b
Substitute to get:
2b + 4(30-b) = 100
Solve for b:
2b+120-4b = 100
-2b = -20
b = 10 (# of birds)
l = 30 - 10 = 20 ( # of lions)
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Cheers,
Stan H.
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