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

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: The perimeter of a square is calculated by multiplying the side length by 4 since all sides are equal. In this case, the side length is 6 cm, so the perimeter is 4 * 6 = 24 cm. Therefore, choice A, 24 cm, is the correct answer. Choices B, C, and D are incorrect because they do not reflect the correct calculation for the perimeter of a square.

Correct Answer: A

Rationale: To find the total distance Jayden rides, you need to add the fractions 5/8 + 3/4. To add these fractions, you must ensure they have a common denominator. In this case, the common denominator is 8. So, 5/8 + 3/4 = 5/8 + 6/8 = 11/8. Since 11/8 can be simplified to 1 3/8, Jayden rides a total of 1 3/8 miles. Choice B (1 1/2 miles), Choice C (1 7/8 miles), and Choice D (2 miles) are incorrect as they do not accurately represent the total distance calculated by adding the two fractions, which is 1 3/8 miles.

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: A

Rationale: The correct answer is A, which is -15. When you multiply -3 by 5, you get -15. The negative sign in front of the 3 indicates a negative value, and when multiplied by a positive number like 5, the result remains negative. Choices B, C, and D are incorrect because they do not reflect the correct multiplication of -3 and 5.

Correct Answer: A

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

Correct Answer: D

Rationale: The formula for the area of a square is given by the square of its side length: Area = side side. For this problem, the side length of the square is 75 centimeters. To find the area, you multiply 75 by itself: 75 75 = 5,625 square centimeters. Thus, the area of the square is 5,625 cm². This shows that option D is correct. Choices A, B, and C are incorrect as they do not correspond to the correct calculation of the area of a square with a side length of 75 centimeters.

Correct Answer: A

Rationale: The absolute value of x is equal to 10 when x is either -10 or 10. Therefore, the correct answer is A. Choices B, C, and D are incorrect because they do not satisfy the equation |x| = 10. For choice B, -11 and 11 do not satisfy the condition. Choices C and D also do not provide solutions that meet the equation's requirement.