Compare the quantities: (a) and (b)
- (a) is greater than (b)
- (b) is greater than (a)
- (a) and (b) are equal (correct answer)
- The relationship cannot be determined
Explanation: When comparing numerical expressions, you need to calculate each quantity first, then determine their relationship. Let's evaluate both expressions step by step. For quantity (a): . For quantity (b): . Since both quantities equal 9, they are equal to each other. Now let's examine why each answer choice is correct or incorrect. Choice A claims that (a) is greater than (b), but since , this is false. Choice B states that (b) is greater than (a), which is also false for the same reason. Choice C correctly identifies that (a) and (b) are equal, since both expressions equal 9. Choice D suggests the relationship cannot be determined, but since we can calculate definite values for both expressions, we can definitely determine their relationship. You might also recognize a shortcut here using the difference of squares formula: . This confirms our answer without having to calculate separately. Study tip: On HSPT quantitative questions, always calculate the actual values when comparing expressions with exponents. Don't try to guess based on the numbers you see - small differences in bases or exponents can dramatically change the results. Also, watch for opportunities to use algebraic shortcuts like the difference of squares formula to save time.