Question

if X² + Y² = 13 and xy=6 find x³ + y³​

Answer 1

Answer:

35

Step-by-step explanation:

9+4=13

then 9=3x3 ,4=2x2

therefore x=3,y=2

27+8=35

Answer 2

(x + y)² = x² + y² + 2xy

=> (x + y)² = 13 + 2(6)

=> (x + y)² = 25

=> (x + y) = 5 or -5

x³ + y³ = (x + y)(x² + y² - xy)

If x + y = 5, x³ + y³ = (5)(13-7) = 30

If x + y = -5, x³ + y³ = (-5)(13-7) = -30