Algebra: The Language of Math
Algebra is about finding the unknown. It is the foundation for almost every question in college entrance exams (UPCAT, USTET, DLSUCET).
Order of Operations (PEMDAS)
Always solve in this order: Parentheses, Exponents, Multiplication/Division (Left to Right), Addition/Subtraction (Left to Right).
Multiplying two negatives? Result is POSITIVE.
Adding two negatives? Result is NEGATIVE (Stay in debt!).
Linear Equations & Inequalities
Solving for x. What you do to one side, you MUST do to the other.
When you Multiply or Divide by a Negative Number, you must FLIP the inequality sign!
-2x < 10 → x > -5
Quadratic Equations (axยฒ + bx + c = 0)
Equations with a squared term. Use factoring or the Quadratic Formula.
Sum of roots = -b/a
Product of roots = c/a
Often, you don't even need to solve for x!
Polynomials & Special Products
Mastering these patterns will save you minutes during the test.
| Name | Pattern |
|---|---|
| Diff. of Two Squares | a² - b² = (a-b)(a+b) |
| Square of Sum | (a+b)² = a² + 2ab + b² |
| Square of Diff. | (a-b)² = a² - 2ab + b² |
Geometry: Lines & Angles
-
1
Complementary: Sum is 90° (Right Angle).
-
2
Supplementary: Sum is 180° (Straight Line).
-
3
Vertical Angles: Always equal.
Triangles Mastery
Common Pythagorean Triples
Save time by memorizing these: 3-4-5, 5-12-13, 8-15-17, and 7-24-25.
The sum of any two sides of a triangle MUST be greater than the third side.
a + b > c
Circles: Pi-Powered Formulas
C = 2πr
A = πr²
Pro Tip: Use π ≈ 3.14 or 22/7 depending on the choices.
Trigonometry: SOH-CAH-TOA
Basic relationships in right-angled triangles.
| Function | Ratio |
|---|---|
| Sin | Opposite / Hypotenuse |
| Cos | Adjacent / Hypotenuse |
| Tan | Opposite / Adjacent |
Functions & Coordinate Geometry
Slope-Intercept Form
y = mx + b
m = slope, b = y-intercept.
Systems of Linear Equations
Solving for two variables (x and y) using two equations.
- 1Substitution: Solve for one variable and plug into the other.
- 2Elimination: Add or subtract equations to cancel a variable.
Word Problems Mastery
Work Shortcut
Together Time =
Distance Formula
Distance = Rate × Time (D-R-T)
Statistics & Probability
Exponents & Logs
| Rule | Expression |
|---|---|
| Product Rule | xª × xº = xªº |
| Quotient Rule | xª / xº = xªº |
| Power Rule | (xª)º = xªº |
Sequences & Series
Finding the nth term of a sequence.
Geometric: aº = a¹rº¹
Entrance Exam Speed Hacks
- 1Back-solving: Plug choices into the equation instead of solving from scratch.
- 2Elimination: Cross out obviously wrong choices (e.g., negative length).
- 3Estimation: Round 4.98 to 5 to quickly find the ballpark answer.
Future Scholar ๐
You've mastered the essentials for the college entrance math exams.