1. **State the problem:** Solve the system of linear equations by graphing and find the number of solutions.
Given system:
$$5x + 5y = 15$$
$$-8x + 2y = 16$$
2. **Convert each equation to slope-intercept form $y = mx + b$:**
For the first equation:
$$5x + 5y = 15$$
Subtract $5x$ from both sides:
$$\cancel{5x} + 5y = 15 - \cancel{5x}$$
$$5y = -5x + 15$$
Divide both sides by 5:
$$\frac{5y}{\cancel{5}} = \frac{-5x}{\cancel{5}} + \frac{15}{5}$$
$$y = -x + 3$$
For the second equation:
$$-8x + 2y = 16$$
Add $8x$ to both sides:
$$\cancel{-8x} + 2y = 16 + \cancel{8x}$$
$$2y = 8x + 16$$
Divide both sides by 2:
$$\frac{2y}{\cancel{2}} = \frac{8x}{\cancel{2}} + \frac{16}{2}$$
$$y = 4x + 8$$
3. **Analyze the slopes and intercepts:**
- First line: slope $m_1 = -1$, intercept $b_1 = 3$
- Second line: slope $m_2 = 4$, intercept $b_2 = 8$
Since the slopes are different ($-1 \neq 4$), the lines intersect at exactly one point.
4. **Find the point of intersection by solving the system algebraically:**
Set the two expressions for $y$ equal:
$$-x + 3 = 4x + 8$$
Add $x$ to both sides:
$$3 = 5x + 8$$
Subtract 8 from both sides:
$$3 - 8 = 5x$$
$$-5 = 5x$$
Divide both sides by 5:
$$\frac{-5}{\cancel{5}} = \frac{5x}{\cancel{5}}$$
$$x = -1$$
Substitute $x = -1$ into $y = -x + 3$:
$$y = -(-1) + 3 = 1 + 3 = 4$$
5. **Final answer:**
- The system has one solution.
- The solution point is $(-1, 4)$.
---
"content" summary:
- Equations in slope-intercept form:
$$y = -x + 3$$
$$y = 4x + 8$$
- One solution at point $(-1, 4)$.
Linear System 4A4Ed1
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.