A farmer owns sheep and chickens. All the sheep have 4 legs and the chickens have 2 legs. He has a total of 8 animals and there is a total of 20 legs.

1. If [tex]\( x \)[/tex] is the number of sheep and [tex]\( y \)[/tex] is the number of chickens, write a system of equations that models this problem and graph it.
2. Determine the number of sheep and chickens.

System of equations:
[tex]\[ x + y = 8 \][/tex]
[tex]\[ 4x + 2y = 20 \][/tex]



Answer :

### Step-by-Step Solution

Given the problem, we need to determine the number of sheep and chickens a farmer owns based on the total number of animals and legs.

#### Step 1: Set Up the System of Equations
Let's define our variables:
- [tex]\( x \)[/tex] = number of sheep
- [tex]\( y \)[/tex] = number of chickens

From the problem, we have the following two pieces of information:
1. The farmer has a total of 8 animals.
2. There is a total of 20 legs.

We can use this information to set up the following system of equations:

[tex]\[ \begin{cases} x + y = 8 \\ 4x + 2y = 20 \end{cases} \][/tex]

#### Step 2: Solve the System of Equations

Equation 1: [tex]\( x + y = 8 \)[/tex]

Equation 2: [tex]\( 4x + 2y = 20 \)[/tex]

Solve Equation 1 for [tex]\( y \)[/tex]:

[tex]\[ y = 8 - x \][/tex]

Substitute [tex]\( y = 8 - x \)[/tex] into Equation 2:

[tex]\[ 4x + 2(8 - x) = 20 \][/tex]

Simplify and solve for [tex]\( x \)[/tex]:

[tex]\[ 4x + 16 - 2x = 20 \\ 2x + 16 = 20 \\ 2x = 4 \\ x = 2 \][/tex]

Now that we have [tex]\( x = 2 \)[/tex], substitute it back into the equation [tex]\( y = 8 - x \)[/tex]:

[tex]\[ y = 8 - 2 \\ y = 6 \][/tex]

Thus, the number of sheep is [tex]\( x = 2 \)[/tex] and the number of chickens is [tex]\( y = 6 \)[/tex].

#### Step 3: Verification

To ensure our solution is correct, we should verify it by plugging these values back into the original equations.

Verification with Equation 1:

[tex]\[ x + y = 2 + 6 = 8 \quad \text{(satisfied)} \][/tex]

Verification with Equation 2:

[tex]\[ 4x + 2y = 4(2) + 2(6) = 8 + 12 = 20 \quad \text{(satisfied)} \][/tex]

Both equations are satisfied, confirming our solution is correct.

#### Step 4: Graphing the System of Equations

While a detailed graph isn't shown here, you can plot both equations on a coordinate plane:

1. For [tex]\( x + y = 8 \)[/tex]:
- The line passes through points [tex]\( (8, 0) \)[/tex] and [tex]\( (0, 8) \)[/tex].

2. For [tex]\( 4x + 2y = 20 \)[/tex]:
- Divide by 2: [tex]\( 2x + y = 10 \)[/tex]
- The line passes through points [tex]\( (5, 0) \)[/tex] and [tex]\( (0, 10) \)[/tex].

The intersection point [tex]\( (2, 6) \)[/tex] represents the number of sheep and chickens, which matches our solution.

### Conclusion

The farmer has 2 sheep and 6 chickens.

Other Questions