If x3 + y3 = 8
x + y = 2
Find the value of xy.
Answer & explanation
Correct answer: option 3
x3 + y3 = 8
x + y = 2
(x + y)3 = x3 + y3 + 3xy (x + y)
(2)3 = 8 + 3xy (2)
8 - 8 = 6xy
0 = 6xy
xy = 0
If x3 + y3 = 8
x + y = 2
Find the value of xy.
Correct answer: option 3
x3 + y3 = 8
x + y = 2
(x + y)3 = x3 + y3 + 3xy (x + y)
(2)3 = 8 + 3xy (2)
8 - 8 = 6xy
0 = 6xy
xy = 0