1
UnitReal Numbers & Properties
Core Concepts
PEMDAS — order of operations: Parentheses → Exponents → Multiply/Divide → Add/Subtract
- Absolute value: \(|a|\) always returns a non-negative value.
- \(|a| = b \Rightarrow a = b \text{ or } a = -b\) (when \(b \geq 0\))
- Number sets: ℕ ⊂ ℤ ⊂ ℚ ⊂ ℝ
▸ Quick Example
\(2 + 3 \times 4^2 - 8 \div 2 = 2 + 3(16) - 4 = 2 + 48 - 4 = 46\)
Answer: 46
What is the value of \(\ 3(2^2) + 4 \cdot 5 - 6 \div 2\ \)?
Which values of \(x\) satisfy \(|2x - 3| = 7\)?
2
UnitAlgebraic Expressions
Core Concepts
Like terms — same variable(s) raised to the same power. Combine coefficients only.
Distributive Property: a(b + c) = ab + ac
- Watch signs: \(-2(3x - 4) = -6x + 8\) (multiply each term)
- Terms: coefficient × variable-part (e.g., \(5x^2\))
▸ Quick Example
\(4x + 2y - x + 3y = 3x + 5y\)
Combine like terms carefully.
Simplify: \((5x^2 - 3x + 2) + (2x^2 + 7x - 5)\)
Simplify: \(-2(3x - 4) + 5x\)
Core Concepts
Solving one-variable equations: isolate \(x\) using inverse operations.
Literal equation: solve for one variable in terms of others.
- Step 1: Distribute / clear parentheses
- Step 2: Collect variable terms on one side
- Step 3: Isolate the variable (divide or multiply)
▸ Quick Example
\(2(x+1) = x + 5 \Rightarrow 2x+2 = x+5 \Rightarrow x = 3\)
Answer: x = 3
Solve for \(x\): \(\ 3(x + 2) = 2x + 10\)
The formula for the area of a triangle is \(A = \dfrac{1}{2}bh\). Solve for \(h\).
Core Concepts
Key rule: flip the inequality sign when multiplying/dividing by a negative
Compound inequalities: \(a \lt x \leq b\) — solve each part simultaneously.
- \(−3 < 2x + 1 \leq 9\): subtract 1 throughout, then divide by 2
- Graph solutions on a number line
▸ Quick Example
\(-2x > 6 \Rightarrow x < -3\) (flip sign when dividing by −2)
Answer: x < −3
Solve the compound inequality: \(-3 \lt 2x + 1 \leq 9\)
For what values of \(x\) is \(5x + 3 \gt 2x + 15\) true?
5
UnitGraphing Linear Equations
Core Concepts
Slope-intercept form: y = mx + b (m = slope, b = y-intercept)
Slope formula: m = (y₂ − y₁) / (x₂ − x₁)
- Convert standard form \(Ax + By = C\) → divide both sides by \(B\)
- Parallel lines: equal slopes; Perpendicular: slopes are negative reciprocals
▸ Quick Example
\(6x - 3y = 12 \Rightarrow y = 2x - 4\), so slope = 2, y-int = −4
Answer: slope = 2
What is the slope of the line passing through \((1,\ 3)\) and \((4,\ 12)\)?
What is the \(y\)-intercept of the line \(4x - 2y = 8\)?
6
UnitSystems of Equations
Core Concepts
Substitution: solve one equation for a variable, substitute into the other.
Elimination: add/subtract equations to cancel a variable.
- If coefficient signs are opposite → add the equations
- If same → subtract one from the other
- Always substitute back to find the second variable
▸ Quick Example
\(y = x + 2,\quad 2x + y = 8 \Rightarrow 2x + (x+2) = 8 \Rightarrow x = 2, y = 4\)
Solution: (2, 4)
Solve the system: \(y = 2x - 1\) and \(3x + y = 14\).
Solve by elimination:
\(2x + 3y = 12\)
\(4x - 3y = 6\)
Core Concepts
Laws of Exponents:
- Product rule: xᵃ · xᵇ = xᵃ⁺ᵇ
- Power rule: (xᵃ)ᵇ = xᵃᵇ
- Negative exp: x⁻ⁿ = 1/xⁿ
- Power of a product: (ab)ⁿ = aⁿbⁿ
▸ Quick Example
\((3x^2)^3 = 3^3 \cdot x^{2 \times 3} = 27x^6\)
Apply power rule to each factor.
Simplify: \(\left(2x^3y^2\right)^3\)
Simplify \(\left(3x^{-2}\right)^2\) and write with a positive exponent.
Core Concepts
FOIL (multiply two binomials): First · Outer · Inner · Last
Factoring trinomials \(x^2 + bx + c\): find two numbers that multiply to c and add to b.
- \((x+p)(x+q) = x^2 + (p+q)x + pq\)
- Always check by expanding your answer
▸ Quick Example
\(x^2 + 5x + 6 = (x+2)(x+3)\) because \(2+3=5\) and \(2\times3=6\)
Answer: (x+2)(x+3)
Expand: \((x + 3)(x - 5)\)
Factor completely: \(x^2 + 7x + 12\)
9
UnitQuadratic Equations
Core Concepts
Quadratic Formula: x = (−b ± √(b²−4ac)) / 2a
Completing the Square: rewrite \(ax^2+bx+c=0\) in the form \((x-h)^2 = k\).
- Discriminant \(\Delta = b^2 - 4ac\): if >0 → 2 real roots; =0 → 1; <0 → no real roots
- Perfect square: \((x-3)^2 = 25 \Rightarrow x - 3 = \pm 5\)
▸ Quick Example
\(x^2 - x - 6 = 0 \Rightarrow (x-3)(x+2)=0 \Rightarrow x=3 \text{ or } x=-2\)
Always verify by substituting back.
Using the quadratic formula, solve \(2x^2 - 5x - 3 = 0\).
Solve for \(x\): \(x^2 - 6x + 9 = 25\)
Core Concepts
Function notation: \(f(x)\) means "the output when the input is \(x\)."
Domain of \(\sqrt{g(x)}\): set \(g(x) \geq 0\) and solve.
- To find \(f(a)\): substitute \(x = a\) everywhere in the formula
- Vertical line test: a graph is a function if every vertical line hits it at most once
▸ Quick Example
\(f(x) = x^2 + 1,\quad f(3) = 9 + 1 = 10\)
Answer: 10
If \(f(x) = x^2 - 3x + 2\), what is \(f(-1)\)?
What is the domain of \(f(x) = \sqrt{2x - 6}\)?
Quiz Complete!
Answer Key & Full Solutions
Answer Key
Q1 C
Q2 B
Q3 A
Q4 C
Q5 B
Q6 D
Q7 C
Q8 A
Q9 B
Q10 D
Q11 A
Q12 C
Q13 B
Q14 D
Q15 A
Q16 C
Q17 B
Q18 D
Q19 A
Q20 C
Step-by-Step Solutions
Q1 (C=29): 3(4) + 20 − 3 = 12 + 20 − 3 = 29
Q2 (B): 2x−3=7 → x=5; 2x−3=−7 → x=−2
Q3 (A): (5+2)x² + (−3+7)x + (2−5) = 7x²+4x−3
Q4 (C): −6x+8+5x = −x+8
Q5 (B): 3x+6=2x+10 → x=4
Q6 (D): Multiply both sides by 2: 2A=bh → h=2A/b
Q7 (C): Subtract 1: −4<2x≤8 → divide by 2: −2<x≤4
Q8 (A): 3x>12 → x>4
Q9 (B): m=(12−3)/(4−1)=9/3=3
Q10 (D): 4x−2y=8 → y=2x−4, y-intercept=−4
Q11 (A): 3x+(2x−1)=14 → 5x=15 → x=3, y=5
Q12 (C): Add equations: 6x=18 → x=3; 2(3)+3y=12 → y=2
Q13 (B): 2³=8, x^(3×3)=x⁹, y^(2×3)=y⁶ → 8x⁹y⁶
Q14 (D): 3²=9, x^(−2×2)=x⁻⁴=1/x⁴ → 9/x⁴
Q15 (A): x²−5x+3x−15=x²−2x−15
Q16 (C): Need pq=12, p+q=7 → p=3,q=4 → (x+3)(x+4)
Q17 (B): Δ=25+24=49, √49=7; x=(5±7)/4 → x=3 or x=−1/2
Q18 (D): (x−3)²=25 → x−3=±5 → x=8 or x=−2
Q19 (A): f(−1)=1+3+2=6
Q20 (C): 2x−6≥0 → x≥3