System Equations Dcdd16
1. **Problem:** Solve the system of equations:
$$y = 3x + 5$$
$$2y = 7x + 2$$
Find the value of $x - y$.
2. **Formula and rules:** To solve a system of linear equations, use substitution or elimination. Here, substitution is straightforward.
3. **Step 1:** From the first equation, $y = 3x + 5$.
4. **Step 2:** Substitute $y$ into the second equation:
$$2(3x + 5) = 7x + 2$$
$$6x + 10 = 7x + 2$$
5. **Step 3:** Rearrange to solve for $x$:
$$6x + 10 = 7x + 2$$
$$10 - 2 = 7x - 6x$$
$$8 = x$$
6. **Step 4:** Substitute $x=8$ back into $y = 3x + 5$:
$$y = 3(8) + 5 = 24 + 5 = 29$$
7. **Step 5:** Calculate $x - y$:
$$8 - 29 = -21$$
**Answer:** $x - y = -21$.
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**Slug:** system-equations
**Subject:** algebra
**Desmos:** {"latex":"y=3x+5","features":{"intercepts":true,"extrema":true}}
**q_count:** 14