Correct Answer: A

Rationale: To solve 3.45 * 0.53, multiply the numbers to get 1.8285. Therefore, the correct answer is A. Choice B is incorrect because it incorrectly moves the decimal point. Choice C is incorrect as it is a fraction of the correct answer. Choice D is incorrect as it results from an error in moving the decimal point.

Correct Answer: A

Rationale: An equivalent fraction is a fraction that may look different in terms of its numerator and denominator but still represents the same value or quantity. This means that when you simplify or expand a fraction, its value remains unchanged. Choice B and C are incorrect because equivalent fractions are not determined by being smaller or larger than another fraction; it is about representing the same quantity. Choice D is incorrect because equivalent fractions may have different numerators as long as the ratio between the numerator and denominator remains the same.

Correct Answer: A

Rationale: To find the expression representing the length of the rectangle in terms of x, we need to consider that the length is six less than two times the width. If we denote the width as x, the length can be expressed as 2x - 6. Therefore, the correct expression is 2x-6 (choice A). Choice B, 6-2x, represents the width subtracted from 6, not the length. Choice C, 6x-2, is not derived from the given information about the relationship between the width and length. Choice D, 3x-4, is not consistent with the relationship provided in the question.

Correct Answer: C

Rationale: To find out how much ammonia is needed for 230 gallons of cleaning solution, you multiply the amount of ammonia needed per gallon by the total gallons of solution required. Therefore, 230 gallons * 6 oz/gallon = 1380 oz of ammonia. Option A ('1380 gallons') and Option B ('6900 gallons') are incorrect as the question asks for the amount of ammonia needed, not the total volume of cleaning solution. Option D ('1400 oz') is incorrect as it does not correctly calculate the amount of ammonia required based on the given information.

Correct Answer: B

Rationale: The total cost (T) consists of the initial charge of $40 plus the additional charges based on the number of tablecloths. The correct expression for T is T = 5c + 3.5r + 40. This accounts for the $5 per circular tablecloth (5c), $3.50 per rectangular tablecloth (3.5r), and the initial $40 charge. Choice A is incorrect as it subtracts the initial charge instead of adding it. Choice C is also incorrect as it subtracts the initial charge and has the coefficients in the wrong positions. Choice D adds the initial charge at the end instead of at the beginning, making it incorrect. Therefore, choice B is the correct representation of the total cost to rent tablecloths.