DepEd MELC reviewer for Grade 8 Mathematics, Quarter 2. Study the rules, worked formulas, and exam hacks below.
1
Linear Equations in Two Variables
The slope-intercept form is y = mx + b, where m is slope and b is the y-intercept.
slope m = (y₂ − y₁) ÷ (x₂ − x₁)
2
Graphing and Slope
| Slope | Line direction |
|---|---|
| Positive | Rises left→right |
| Negative | Falls left→right |
| Zero | Horizontal |
| Undefined | Vertical |
💡 Exam Hack
Slope = rise over run. Count up/down then left/right between two points.
3
Systems of Linear Equations
Solve by graphing, substitution, or elimination. The solution is the point where the lines intersect.
⚠️ Common Mistake
Parallel lines (same slope) have NO solution; identical lines have INFINITE solutions.
4
Worked Example
Find the slope through (1, 2) and (4, 11).
m = (11 − 2) ÷ (4 − 1) = 9 ÷ 3 = 3
So the line rises 3 units for every 1 unit right.
📌 Quick Recap — Master These
Before your test, make sure you can confidently do each of the following:
- Explain and apply Linear Equations in Two Variables.
- Explain and apply Graphing and Slope.
- Explain and apply Systems of Linear Equations.
- Explain and apply Worked Example.
Re-read any section above where you hesitate, then try the worked example again without looking.