Question:
If the sum of two numbers x and y is 12 and their product is 27, then find the sum of their cubes.
यदि दो संख्याओं x और y का योग 12 है और उनका गुणनफल 27 है, तो उनके घनों का योग ज्ञात कीजिए।
Options:
- a) 576
- b) 657
- c) 756
- d) 765
- a) 576
- b) 657
- c) 756
- d) 765
correct answer : c)
Explanation:
x + y = 12, xy = 27. x^3 + y^3 = (x + y)^3 – 3xy(x + y) = 12^3 – 3*27*12 = 1728 – 972 = 756.
x + y = 12, xy = 27. x^3 + y^3 = (x + y)^3 – 3xy(x + y) = 12^3 – 3*27*12 = 1728 – 972 = 756.