A farm raises pigs and chickens. The farmer has a total of 66 animals. One day he counts the legs of all his animals and realizes he has a total of 174 legs. How many chickens does the farmer have? Please help me this is to hard!

The farmer has 45 chickens

Step-by-step explanation:

Let the number of pigs = p

Let the number of chickens = c

Total animals = 66

p + c = 66 (I)

c = 66 - p

A pig has 4 legs. so 'p' number of pigs has p*4 = 4p legs

A chicken has 2 legs. so 'c' number of pigs has c*2 = 2c legs

Total legs = 174

4p + 2c = 174 (II)

Substitute c = 66 -p in equation (II)

4p + 2(66 - p) = 174

4p + 2*66 - 2*p = 174

4p + 132 - 2p = 174

4p - 2p + 132 = 174             {Combine like terms}

       2p + 132 = 174                     {Subtract 132 from both sides}

             2p    = 174 - 132          

             2p     = 42                       {Divide both sides by 2}

                p  = 42/2

               p = 21

Plugin p =21 in equation (I)

21 + c = 66

        c = 66 -21

c = 45

The farmer has 45 chickens

step-by-step explanation: a reaction is first order. if the initial reactant concentration is 0.0200 m, and 25.0 days later the concentration is 6.25 x 10-4 m, then its half-life is:

14.3

step-by-step explanation:

add all the numbers together.

9 + 12 + 15 + 16 + 17 + 17 = 86

now, divide 86 by how many numbers we have: 6.

86 / 6 = 14.3