Answers

2015-08-05T15:40:15+05:30
X + y = 1
Squaring on both sides,
x²+y²+2xy = 1
x²+y² = 1 - 2xy    ....... (1)

x³+y³ = 19
(x+y)(x²+y²-xy) =19
x²+y²-xy =19     [Since x + y = 1]
x²+y² =19 + xy       .................(2)

From the equations (1) and (2)

1 - 2xy = 19 + xy

3xy = -18

xy = -6

Now, substitute the value of xy in equation (2)
x²+y² =19 + (-6) = 13


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