If (x + y) = 17, xy = 9, then what is the value of x3 + y3?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 4454.
x3 + y3 = (x + y)(x2 - xy + y2) ...(i)
Now, (x + y)2 = x2 + 2xy + y2
⇒ x2 + y2 = 289 - 18
⇒ x2 + y2 = 271
Putting values in equation (i),
⇒ x3 + y3 = (17)(271 - 9)
⇒ x3 + y3 = 17 × 262
⇒ x3 + y3 = 4454