12. √171 - √19 =
Answer: D
√171 - √19 = √76
The expression √171 - √19 simplifies to √76, indicating that the difference between these two square roots results in this specific square root value.
A) √152
Option A is incorrect because √152 does not equal the result of √171 - √19. In fact, √152 is greater than √171 - √19, indicating that it is not the correct simplification of the expression.
B) √133
Option B is also incorrect. The value of √133 is not equivalent to the difference between √171 and √19. This option represents a value that does not align with the calculated result of the expression.
C) √95
Option C is incorrect since √95 does not represent the difference between √171 and √19. This option yields a value that is less than the actual result of the expression, making it an unsuitable choice.
D) √76
Option D is correct because it accurately represents the result of the expression √171 - √19. This option is the only one that correctly simplifies the given square root difference.
Conclusion
The correct answer, √76, is the valid simplification of the expression √171 - √19. All other options fail to represent the correct value, either being larger or smaller than the actual result. Thus, D is definitively the right choice based on the mathematical operations involved.