Questions 1 To 20: Select The Best Answer For Each Question
Questions 1 To 20select The Best Answer To Each Question Note That A
Questions 1 to 20: Select the best answer to each question. Note that a question and its answers may be split across a page break, so be sure that you have seen the entire question and all the answers before choosing an answer.
Paper For Above instruction
The given set of questions primarily revolves around algebraic concepts, including factoring, simplifying expressions, solving equations, and graphing polynomial functions. Throughout these questions, a solid understanding of algebraic methods such as factoring quadratic and higher-degree polynomials, solving for variables, and interpreting functions graphically is essential. This paper explores these core algebraic topics, elucidating strategies for solving complex problems involving polynomial expressions.
Factoring Polynomial Expressions
Factoring is a fundamental skill in algebra, crucial for simplifying expressions and solving equations. Questions such as 1, 2, 7, and 17 focus on factoring quadratic and higher-degree polynomials. For example, Question 1 asks to completely factor the quadratic expression y² + 12y + 35. Recognizing this as a standard quadratic, factoring involves finding two numbers that multiply to 35 and add to 12, which are 7 and 5. Therefore, the factorization is (y + 7)(y + 5), corresponding to answer B.
Similarly, Question 2 involves the difference of squares, 16x⁴ - 81y⁴. Recognizing that both terms are perfect squares allows us to apply the difference of squares formula: a² - b² = (a + b)(a - b). Here, 16x⁴ = (4x²)² and 81y⁴ = (9y²)². Thus, the expression factors as (4x² + 9y²)(4x² - 9y²). Further factoring the second term, 4x² - 9y², again as a difference of squares yields (2x + 3y)(2x - 3y). The final factorization is thus (4x² + 9y²)(2x + 3y)(2x - 3y), but among the options, answer C reflects the correct factoring structure.
Question 7 involves factoring r² - 2r + 1, which is a perfect square trinomial. Recognizing that it factors as (r - 1)² or (r - 1)(r - 1). The answer B, (r - 1)(r - 1), is correct.
Question 17 asks for factoring 2a³ - 128. Recognizing that 128 is 2^7, and factoring out common factors yields 2(a³ - 64). Since 64 = 4³, the difference of cubes formula applies: a³ - b³ = (a - b)(a² + ab + b²). Thus, a³ - 64 = (a - 4)(a² + 4a + 16). Multiplying by 2, the factorization is 2(a - 4)(a² + 4a + 16), matching answer B.
Simplifying Expressions
Questions 3, 4, 8, 10, 14, 19, and 20 involve simplifying algebraic expressions. The key is to combine like terms, apply distributive laws, and use identities.
Question 3 simplifies 2ab⁴ - 3a²b² - ab⁴ + a²b². Combining like terms:
- 2ab⁴ - ab⁴ = ab⁴
- -3a²b² + a²b² = -2a²b²
Resulting in ab⁴ - 2a²b², answer B.
Question 4 involves squaring (x - 2y):
(x - 2y)² = x² - 4xy + 4y², answer D.
Question 8 involves factoring 16t³ - 50t² + 36t. First, factor out 2t:
2t(8t² - 25t + 18). Factoring the quadratic:
8t² - 25t + 18. Find two numbers that multiply to (8)(18) = 144 and sum to -25, which are -9 and -16.
However, since -9 and -16 sum to -25 and multiply to 144, the quadratic factors as:
(8t - 9)(t - 2).
Multiplying back with 2t, the full factorization is answer B: 2t(8t - 9)(t - 2).
Solving Equations
Questions 5, 14, and 15 involve solving algebraic equations.
Question 5: 3z³ - 300z = 0. Factor out 3z:
3z(z² - 100) = 0.
Set each factor equal to zero:
3z = 0 ⇒ z = 0.
z² - 100 = 0 ⇒ z² = 100 ⇒ z = ±10.
Thus, solutions are z = 0, z = 10, and z = -10, answer C.
Question 14: x² + 4x - 45 = 0. Factor:
(x + 9)(x - 5) = 0, giving solutions x = -9 and x=5, answer A.
Quadratic and Polynomial Graphing
Question 20 involves graphing:
f(x) = x³ - 1.
This polynomial has an inflection point at x = 0, and the graph passes through points where f(x) = 0, i.e., x³ - 1 = 0 ⇒ x = 1.
The graph's shape involves a cubic curve crossing the x-axis at x=1, with standard cubic behavior.
Conclusion
Understanding the principles of polynomial factoring, including recognizing special products like perfect squares, difference of squares, and sum/difference of cubes, is essential. Simplification of algebraic expressions requires careful combination of like terms and application of identities. Solving equations typically involves isolating the variable, factoring, and employing quadratic formulas when necessary. Graphing polynomial functions such as cubic equations provides visual insights into their roots and end behavior.
The mastery of these techniques enhances problem-solving efficiency and accuracy in algebra, serving as a foundation for advanced mathematics.
References
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