Nursing Elites

1. Simplify (x^2 - y^2) / (x - y)

• A. x + y
• B. x - y
• C. 1
• D. (x + y)/(x - y)

Correct answer: A

Rationale: The expression 𝑥^2 - 𝑦^2 is a difference of squares, which follows the identity: 𝑥^2 - 𝑦^2 = (𝑥 + 𝑦)(𝑥 - 𝑦). Therefore, the given expression becomes: (𝑥^2 - 𝑦^2) / (𝑥 - 𝑦) = (𝑥 + 𝑦)(𝑥 - 𝑦) / (𝑥 - 𝑦). Since (𝑥 - 𝑦) appears in both the numerator and the denominator, they cancel each other out, leaving 𝑥 + 𝑦. Thus, the simplified form of (𝑥^2 - 𝑦^2) / (𝑥 - 𝑦) is 𝑥 + 𝑦. Therefore, the correct answer is A (x + y). Option B (x - y) is incorrect as it does not result from simplifying the given expression. Option C (1) is incorrect as it does not account for the variables x and y present in the expression. Option D ((x + y)/(x - y)) is incorrect as it presents the simplified form in a different format than the correct answer.

2. Which statement best describes the rate of change?

• A. Every day, the snow melts 10 centimeters.
• B. Every day, the snow melts 5 centimeters.
• C. Every day, the snow increases by 10 centimeters.
• D. Every day, the snow increases by 5 centimeters.

Correct answer: B

Rationale: The rate of change refers to how one quantity changes concerning another quantity. In this scenario, the rate of change is the amount of snow melting per day, which is 5 centimeters. This is determined by the slope of the graph, indicating a decrease in snow depth. Choices C and D incorrectly describe an increase in snow depth, while choice A exaggerates the rate of snow melting compared to the actual value of 5 centimeters per day.

3. What is the least common denominator of two fractions?

• A. The smallest number that is a multiple of both denominators
• B. The smallest number that both fractions can divide into evenly
• C. The least common multiple of both denominators
• D. The greatest common factor of both denominators

Correct answer: C

Rationale: The least common denominator of two fractions is the least common multiple of both denominators. This is because the least common denominator is the smallest number that both denominators can divide into evenly, ensuring that both fractions can be expressed with a common denominator. Choice A is incorrect as the least common denominator is a multiple of both denominators, not a number that multiplies into both. Choice B is incorrect because the common denominator needs to be a multiple of both denominators, not just a number they can divide into evenly. Choice D is incorrect as the greatest common factor is not used to find the least common denominator, but rather the least common multiple.

4. What must you always use in all math?

• A. PEMDAS
• B. Variables
• C. Conversion factors
• D. Estimation

Correct answer: A

Rationale: The correct answer is A: PEMDAS. PEMDAS stands for the order of operations: Parentheses, Exponents, Multiplication and Division (left to right), Addition and Subtraction (left to right). It is a fundamental rule to follow in mathematics to ensure calculations are done correctly. Choices B, C, and D are incorrect as they do not encompass the essential rule that PEMDAS provides for solving mathematical expressions.

5. Using the chart below, which equation describes the relationship between x and y?

• A. x = 3y
• B. y = 3x
• C. y = 1/3x
• D. x/y = 3

Correct answer: B

Rationale: The correct equation that describes the relationship between x and y based on the chart is y = 3x. This is because each y-value in the chart is 3 times the x-value. Choice A (x = 3y) is incorrect as it implies x is 3 times y, which is the opposite of the relationship shown in the chart. Choice C (y = 1/3x) is incorrect since the relationship in the chart indicates y is 3 times x, not a third of x. Choice D (x/y = 3) is incorrect as it represents a ratio between x and y equal to 3, which is not in line with the relationship depicted in the chart.

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