Question
(1) Use substitution to solve the system of equations. \( \begin{array}{l}x=3-2 y \\ 3 y=2 x+8 \\ \text { (1)) How can you use substitution in this problem? } \\ \text { (1) Substitute ? for ? }\end{array} \)
Ask by Ray Robbins. in the United States
Jan 24,2025
Real Tutor Solution
Tutor-Verified Answer
Answer
Use substitution by replacing \( x \) with \( 3 - 2y \) in the second equation.
Solution
To solve the system of equations using **substitution**, follow these steps:
\[
\begin{cases}
x = 3 - 2y \quad \text{(Equation 1)} \\
3y = 2x + 8 \quad \text{(Equation 2)}
\end{cases}
\]
### (1) How can you use substitution in this problem?
**Substitution** involves solving one of the equations for one variable and then substituting that expression into the other equation. In this case:
- **Equation 1** already solves for \( x \): \( x = 3 - 2y \).
This allows us to substitute the expression for \( x \) from Equation 1 into Equation 2, eliminating \( x \) and allowing us to solve for \( y \).
### (2) Substitute ___ for ___.
**Substitute \( 3 - 2y \) for \( x \).**
Here's how it's done:
1. **Start with Equation 2:**
\[
3y = 2x + 8
\]
2. **Substitute \( x \) from Equation 1 into Equation 2:**
\[
3y = 2(3 - 2y) + 8
\]
3. **Now, solve for \( y \):**
\[
3y = 6 - 4y + 8 \\
3y + 4y = 14 \\
7y = 14 \\
y = 2
\]
4. **Find \( x \) using Equation 1:**
\[
x = 3 - 2(2) \\
x = 3 - 4 \\
x = -1
\]
**Solution:** \( x = -1 \) and \( y = 2 \).
---
**Summary:**
- **Use Substitution By:** Substituting \( 3 - 2y \) for \( x \) in the second equation.
This method efficiently reduces the system to a single equation with one variable, making it easier to solve.
**Answer:**
Use substitution by replacing x with 3 – 2y. Specifically, substitute 3 − 2y for x in the second equation.
Reviewed and approved by the UpStudy tutoring team
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Extra Insights
To use substitution in this system of equations, we start with the first equation, \( x = 3 - 2y \). This means we can substitute \( x \) in the second equation \( 3y = 2x + 8 \). So, we simply replace \( x \) with \( 3 - 2y \) and solve for \( y \). Now, substitute \( 3 - 2y \) for \( x \) in the second equation \( 3y = 2x + 8 \) to get \( 3y = 2(3 - 2y) + 8 \). From there, it's just a matter of simplifying and solving for \( y \)!