Question

Read the following situation:

Answer 1

Answer:

Hi, let's turn the word problem into a set of equations:

Let's say that x = # of chickens, and y = # of pigs

If there are 13 animals altogether, that means that

x + y = 13

If there are 40 legs together, we know that chickens have 2 legs, while pigs have 4, so the total number of legs would be:

2x + 4y = 40

We now have two different equations, with the same two variables, so we can rearrange and substitute one equation into the other to solve. We can rearrange the first equation as:

x + y = 13

x = 13 - y

Let's plug this expression for "x" into the second equation:

2(13-y) + 4y = 40

Now we have an equation with only one variable, so we can use algebra to solve for y:

26 - 2y + 4y = 40

2y = 14

y = 7, there must be 7 pigs.

From the first equation that we rearranged,

x = 13 - y

Now that we know the numerical value of "y", we can plug that in:

x = 13 - 7

x = 6, there must be 6 chickens