If 7x2 + y2 = 67, xy = 6 (x, y > 0)
find 2x3 + y3 + 8.
Answer & explanation
Correct answer: option 1
By Putting x = 3 and y = 2
These values are satisfying the equations:
⇒ 7x2 + y2 = 67
⇒ 7(3)2 + (2)2 = 67
⇒ 67 = 67
Put these values and find:
⇒ 2x3 + y3 + 8 = 2(3)3 + (2)3 + 8 = 54 + 8 + 8 = 70