Solve the system of linear equations: $x = 4$ and $3x - 2y = 6$ graphically.
Generated by claude-sonnet-4-6 · 2026-06-15 10:35 · grounding rag
Model Answer
For x = 4: This is a vertical line parallel to the y-axis passing through x = 4.
Points: (4, 0), (4, 2), (4, –2)
For 3x – 2y = 6: Rewrite as $y = \dfrac{3x-6}{2}$
| x | 0 | 2 | 4 |
|---|---|---|---|
| y | –3 | 0 | 3 |
Points: (0, –3), (2, 0), (4, 3)
Plot both lines on the graph. The line x = 4 is vertical; the line 3x – 2y = 6 passes through (0, –3) and (2, 0).
The two lines intersect at (4, 3).
∴ Solution: x = 4, y = 3
Source: Chapter 3, Section 3.2 — Graphical Method of Solution of a Pair of Linear Equations
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Explanation
- Examiners expect a table of values for the non-vertical equation and at least two named points for the vertical line.
- The vertical line x = 4 scores easy marks — just state it is parallel to the y-axis through x = 4.
- Substitute the answer back to verify: 3(4) – 2(3) = 12 – 6 = 6 ✓
- Always state the solution clearly as a coordinate pair at the end — that line carries marks.