On A Farm There Are Horses And Chickens. There Are Total Of 28 Heads And 92 Legs. How Many Horses Are On The Farm?

(92 - 2*28)/2 = 18
There are 18 horses and 10 chickens.

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Double the number of heads to get 2 legs per animal. Each horse has 2 "excess legs". To find the number of horses, we compute the number of excess legs and divide by 2.