Answer:
1 spider, 3 cows, 5 birds.
Step-by-step explanation:
Cows (C): 4 legs, 2 eyes.
Birds (B): 2 legs, 2 eyes.
Spiders (S): 8 legs, 4 eyes.
The number of legs and eyes are given, respectively by:
Multiplying the second equation by -2 and adding it to the first one gives us the number of birds:
Rewriting the original equations with B =5:
Since the number of cows cannot be negative, and both C and S must be odd numbers, the only possible value of S is 1: