Correct Answer: C

Rationale: When you see something like (a + b)², it means you're multiplying (a + b) by itself: (a + b)² = (a + b) (a + b) To expand this, we use the distributive property (which says you multiply each term in the first bracket by each term in the second bracket): Multiply the first term in the first bracket (a) by both terms in the second bracket: a a = a² a b = ab Multiply the second term in the first bracket (b) by both terms in the second bracket: b a = ab b b = b² Now, add up all the results from the multiplication: a² + ab + ab + b² Since ab + ab is the same as 2ab, we can simplify it to: a² + 2ab + b² So, (a + b)² = a² + 2ab + b². This is known as a basic polynomial identity, and it shows that when you square a binomial (a two-term expression like a + b), you get three terms: the square of the first term (a²), twice the product of the two terms (2ab), and the square of the second term (b²). Therefore, the correct answer is C (a² + 2ab + b²)

Correct Answer: C

Rationale: To determine the smallest decimal, we look at the digits after the decimal point. In this case, 2.002 is the smallest because it has the least value in the thousandths place. Choice A, 2.22, has a higher value in the hundredths place making it larger. Choice B, 2.02, has a higher value in the hundredths place compared to 2.002. Choice D, 2.2, is larger than 2.002 as it has a higher value in the tenths place.

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.

Correct Answer: C

Rationale: To create a 5:1 solution in 2.5 liters, 0.5 liters are needed for HCl, which translates to 5 grams. The correct answer is 5 grams, as this amount corresponds to the 5:1 ratio specified in the solution. Choices A, B, and D are incorrect because they do not align with the 5:1 ratio and the volume of the solution.

Correct Answer: A

Rationale: To multiply fractions, multiply the numerators together and the denominators together. Multiplying 3/5 by 5/7 gives (3*5)/(5*7) = 15/35. This fraction simplifies to 3/7 by dividing the numerator and denominator by their greatest common factor, which is 5. Therefore, the correct answer is 3/7. Choices B, C, and D are incorrect as they do not result from multiplying 3/5 by 5/7.