10 questions · Form 2 Mathematics Bab 2: Factorisation and Algebraic Fractions
Factorise 2x² + 5x + 3.
Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.
1. Factorise 2x² + 5x + 3.
Answer: B
Using cross-multiplication: (2x + 3)(x + 1) = 2x² + 2x + 3x + 3 = 2x² + 5x + 3.
2. Expand (2x + 3)(x - 4).
Answer: A
Using FOIL: (2x)(x) + (2x)(-4) + (3)(x) + (3)(-4) = 2x² - 8x + 3x - 12 = 2x² - 5x - 12.
3. Factorise completely: 3x² - 12.
Answer: B
First factor out 3: 3(x² - 4). Then apply difference of squares: 3(x + 2)(x - 2).
4. Express x² - 9x + 3 in its simplest form.
Answer: B
Factorise the numerator: (x + 3)x - 3x + 3 = x - 3.
5. Factorise by grouping: ax + ay + bx + by.
Answer: C
Group in pairs: a(x + y) + b(x + y) = (a + b)(x + y).
6. Simplify: (4mn) ÷ (2m² / 3n).
Answer: A
Change division to multiplication by reciprocal: (4mn) × (3n2m²) = 12mn2m²n = 6m.
7. Expand: 2(x - 3) - 3(2 - x).
Answer: A
Expand each term: 2x - 6 - 6 + 3x = (2x + 3x) + (-6 - 6) = 5x - 12.
8. Factorise x² - 49.
Answer: B
Using difference of two squares a² - b² = (a + b)(a - b): x² - 7² = (x + 7)(x - 7).
9. Simplify the expression: (2x3) + (x4).
Answer: B
Find the LCM of 3 and 4, which is 12: (2x × 412) + (x × 312) = 8x12 + 3x12 = 11x12.
10. Simplify: 1 - x - 23.
Answer: A
Combine under common denominator 3: 3 - (x - 2)3 = 3 - x + 23 = 5 - x3.