. If x + y = 3, x^2 + y^2 = 5 then xy is
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Answered by
3
Answer:
2
Step by step:
x+y=3
squaring both sides;
(x+y)^2=3^2
x^2+y^2+2xy=9 [ (a+b)^2=a^2+b^2+2ab]
5+2xy=9
2xy=9-5
2xy=4
xy=4/2
xy=2
Answered by
2
Hey mate!!!
We are given
x + y = 3
and
{x}^{2} + {y}^{2} = 5
we have to find XY
so by using
(x + y) {}^{2} = {x}^{2} + {y}^{2} + 2xy
we have
(x + y) {}^{2} = {x}^{2} + {y}^{2} + 2xy \\ = > (3) {}^{2} = 5 + 2xy \\ 2xy + 5 = 3 {}^{2} \\ 2xy + 5 = 9 \\ 2xy = 9 - 5 \\ 2xy = 4 \\ xy = 4 \div 2 \\ xy = 2
XY = 2
Hope it helps dear friend ☺️✌️✌️
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