Simplify the radical expression: √289 − √625 ÷ √25, using standard order of operations (division before subtraction). Provide the exact integer result.

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:

  • Expression: √289 − √625 ÷ √25.
  • Standard order: evaluate square roots, perform division, then subtract.
  • All roots are principal (non-negative) square roots.


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:

Compute square roots: √289 = 17; √625 = 25; √25 = 5.Perform division: √625 ÷ √25 = 25 ÷ 5 = 5.Subtract: 17 − 5 = 12.


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

More Questions from Simplification

Discussion & Comments

No comments yet. Be the first to comment!
Join Discussion