What is the result of dividing 8 by 4?

Correct Answer: A

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: C

Rationale: The difference between two numbers is found by subtracting one from the other. When two numbers are equal, subtracting them results in 0, because any number minus itself is always 0. Therefore, the difference between two equal numbers is always zero, making option C the correct answer. Option A ('Negative') and option B ('Positive') are incorrect as they do not represent the result of subtracting two equal numbers, which always yields zero. Option D ('Not enough information') is also incorrect as the difference between two equal numbers is definitively known to be zero.

Correct Answer: D

Rationale: The tree grows at an average rate of 4.2 inches per day. To find the rate of change per month, multiply the daily growth rate by the number of days in a month (30 days): 4.2 inches/day 30 days = 126 inches per month. Therefore, the rate of change in the tree's height is 126 inches per month, making option D the correct answer. Option A is incorrect because it miscalculates the rate based on daily growth. Option B is incorrect as it doesn't account for the total days in a month. Option C is incorrect as it overestimates the monthly growth rate.

Correct Answer: B

Rationale: The correct answer is B: 'Positive number.' When you subtract one negative number from another negative number, the result can be a positive number. For example, the difference between -5 and -3 is 2, which is a positive number. Choice A, 'Negative number,' is incorrect because the result of subtracting two negative numbers can be positive. Choice C, 'Zero,' is incorrect because the difference between two negative numbers is not always zero. Choice D, 'Not enough information,' is incorrect because there is enough information to determine that the difference between two negative numbers can be a positive number.

Correct Answer: D

Rationale: When simplifying the expression 3x - 5x + 2, start by combining like terms. -5x is subtracted from 3x to give -2x. Adding 2 at the end gives the simplified expression -2x. Therefore, the correct answer is -2x. Choice A, -2x + 2, incorrectly adds 2 at the end. Choice B, -8x, incorrectly combines the coefficients of x without considering the constant term. Choice C, 2x + 2, incorrectly adds the coefficients of x without simplifying.

Correct Answer: A

Rationale: To simplify the expression 2x + 3x - 5, follow these steps: Identify and combine like terms. The terms 2x and 3x are both 'like terms' because they both contain the variable x. Add the coefficients of the like terms: 2x + 3x = 5x. Simplify the expression. After combining the like terms, the expression becomes 5x - 5, which includes the simplified term 5x and the constant -5. Thus, the fully simplified expression is 5x - 5, making Option A the correct answer. This method ensures all terms are correctly simplified by combining similar elements and retaining constants.

Correct Answer: A

Rationale: To determine how many times larger the first cell is compared to the second cell, divide the diameter of the first cell by the diameter of the second cell: 0.1 / 0.05 = 2. Therefore, the first cell is 2 times larger than the second cell. Choice B, C, and D are incorrect because they do not provide the accurate calculation for the size difference between the two cells.

Correct Answer: B

Rationale: From Equation 1: 2x + y = 0. Solve for y: y = -2x. Substitute y = -2x into Equation 2: x - 2(-2x) = 8. Simplify to x + 4x = 8, then 5x = 8, and x = 8 · 5 = 1.6. Substitute x = 1.6 back into y = -2x to find y = -3.2. Therefore, one solution is (1.6, -3.2). To find the second solution, use -1.6 for x to get (-1.6, 3.2). Thus, the correct answer is B, representing the solutions (1.8, -3.6) and (-1.8, 3.6). Choices A, C, and D contain incorrect values that do not match the solutions derived from solving the system of equations.

Correct Answer: A

Rationale: To find the total pounds of apples Eric buys, you need to multiply the pounds of apples bought each week (5 1/2 pounds) by the number of weeks (4 weeks). When you multiply 5 1/2 by 4, you get 22 pounds. Therefore, the correct answer is A. Choices B, C, and D are incorrect because they do not accurately calculate the total pounds purchased over the four weeks.