If X=a2 −b2 , Y=30 and a+b=15, then
2023
If X=a2 −b2 , Y=30 and a+b=15, then
- A.
X is lesser than Y if a = b
- B.
X is greater than Y if a > b
- C.
Y is greater than X if a = b
- D.
More than one of the above
- E.
None of the above
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Correct answer: D
Given: X = a^2 - b^2, Y = 30, and a + b = 15.
Step 1: Factor X using the difference of squares formula: X = (a - b)(a + b).
Step 2: Substitute the known value of (a + b) = 15 into the equation for X. This gives X = 15(a - b).
Step 3: Compare X and Y. We need to compare 15(a - b) with 30. Dividing both sides by 15, we compare (a - b) with 2.
Step 4: Analyze the condition a = b. If a = b, then (a - b) = 0. Thus, X = 15(0) = 0. Since Y = 30, X < Y and Y > X.
Step 5: Analyze the condition a > b. If a > b, then (a - b) > 0. However, X > Y only if (a - b) > 2. Therefore, a > b alone is not sufficient.
Conclusion: Options stating X < Y and Y > X when a = b are both valid. Thus, the option indicating more than one statement is correct is the right choice.
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