Answer:
20x-10
Explanation:
Cows have
legs and 3 toes on each leg, if we want to find the number of toes of ONE cow we have to multiply the legs by the toes giving the following:

But we have two cows so (1) we have to multiply it by 2 giving a total of:

By the other hand chickens have
legs and 7 toes on each leg, if we want to find the number of toes we have to multiply the legs by the toes giving the following:

To find the total amount of toes we have to add (2) and (3)
