Answers

  • Brainly User
2014-08-31T20:42:19+05:30
Taking cube both sides we get    (x+y)^3=-4^3=-64
now expanding   x^3+ y^3+3xy(x+y)=-64
putting x+y=-4   we get
x^3+y^3+3xy(-4)=-64
or x^3+y^3-12xy+64=0
2 2 2
2014-08-31T20:43:41+05:30
x³ + y³ - 12xy + 64
x³ + y³ + 4³ - 3(4xy)       (64 = 4³)
(x + y + 4)(x² + y² + 4²  - xy - 4y - 4x)
x + y = - 4
(- 4 + 4) * (x² + y² + 4²  - xy - 4y - 4x)
0 * (x² + y² + 4²  - xy - 4y - 4x)
= 0
6 3 6
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