Difficulty: Easy
Correct Answer: 12
Explanation:
Introduction / Context:
This test checks the correct application of order of operations to square roots and division. Remember that division is performed before subtraction unless parentheses indicate otherwise.
Given Data / Assumptions:
Concept / Approach:
First compute each square root exactly. Then divide the results as indicated. Finally, finish with the subtraction. Avoid prematurely subtracting before handling the division to the right.
Step-by-Step Solution:
Verification / Alternative check:
Rewriting: 17 − (25/5) = 17 − 5 = 12. No other operations apply, confirming the result.
Why Other Options Are Wrong:
17 corresponds to ignoring the division term. 15 and 10 arise from mixing addition or miscomputing 25/5. −8/5 comes from an incorrect ordering or sign error.
Common Pitfalls:
Subtracting 25 first or treating √625 ÷ √25 as √(625/25) only after subtraction; although √625 ÷ √25 equals √(625/25) numerically, the subtraction must wait until the division is completed.
Final Answer:
12
Discussion & Comments