Certainly! Let's go through the elimination method step by step in detail for the problem involving the costs of soft tacos and burritos.
Step-by-Step Elimination Method
We started with our two equations:
- \( 3t + 3b = 11.25 \) (Equation 1)
- \( 4t + 2b = 10.00 \) (Equation 2)
Our goal is to eliminate one variable to solve for the other. We can do this by manipulating the equations in such a way that when we combine them, one of the variables cancels out.
Step 1: Simplify Equation 1
First, we simplify Equation 1. Since all terms can be divided by 3, we do this:
\[
3t + 3b = 11.25
\]
Dividing the entire equation by 3 gives:
\[
t + b = \frac{11.25}{3} = 3.75
\]
Let's call this Equation 3:
- \( t + b = 3.75 \)
Step 2: Adjust Equation 3 for Elimination
Now, we want to manipulate Equation 3 to facilitate the elimination of the variable \( b \).
To do this, we can multiply Equation 3 by 2 so that the coefficient in front of \( b \) matches that in Equation 2 when we subtract:
\[
2(t + b) = 2(3.75)
\]
This yields:
\[
2t + 2b = 7.50 \quad \text{(Equation 4)}
\]
Step 3: Write the Two Equations for Elimination
Now we have:
- Equation 4: \( 2t + 2b = 7.50 \)
- Equation 2: \( 4t + 2b = 10.00 \)
Both equations have \( 2b \) on the left side. We are now ready to eliminate \( b \) by subtracting one equation from the other.
Step 4: Subtract Equation 4 from Equation 2
Now, we'll subtract Equation 4 from Equation 2:
\[
(4t + 2b) - (2t + 2b) = 10.00 - 7.50
\]
When we perform this subtraction, the \( 2b \) terms cancel out:
\[
4t + 2b - 2t - 2b = 10.00 - 7.50
\]
This simplifies to:
\[
(4t - 2t) + (2b - 2b) = 2.50
\]
Which simplifies to:
\[
2t = 2.50
\]
Step 5: Solve for \( t \)
Now we can solve for \( t \):
\[
t = \frac{2.50}{2} = 1.25
\]
Step 6: Substitute \( t \) back to find \( b \)
Now that we have \( t \), we can substitute it back into one of our earlier equations to find \( b \). We can use Equation 3:
\[
t + b = 3.75
\]
Substituting \( t = 1.25 \):
\[
1.25 + b = 3.75
\]
Now solve for \( b \):
\[
b = 3.75 - 1.25 = 2.50
\]
Final Result
We now have the costs as follows:
- Cost of one soft taco \( t = 1.25 \)
- Cost of one burrito \( b = 2.50 \)
Summary of the Elimination Method
In summary, the elimination method involves:
- Simplifying one or both equations if possible.
- Manipulating the equations (by multiplication or division) to make the coefficients of one variable match.
- Subtracting one equation from the other to eliminate that variable.
- Solving for the remaining variable.
- Substituting back to find the initially eliminated variable.
This approach is efficient when the coefficients lend themselves to easy manipulation, as we showed in our example.