Odpowiedzi

2009-12-15T19:56:51+01:00
X+y=12/ ( -2)
x2+y2= 126

-2x - 2y = - 24
2x +2y = 126
0 = 102
2009-12-15T20:05:27+01:00
Niech x+y=12 i x2+y2= 126. Oblicz x*y.
X+Y=12 |-Y
X2+Y2=126
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x=12-y
(12-y)2+y2=126
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x=12-y
(12-y)(12-y)+y2=126
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x=12-y
144-12y-12y-y2=126
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x=12-y
144-24y-y2=126|-144
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x=12-y
-24y-y2=-18 |+y2
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x=12-y
-24y=-18+y2 |:(-24)
___(odtąd nie jestem pewna)
x=12-y
y=0,75+ y2|-y2
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x=12-y
y+y2=0,75
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x=12-y
y3=0,75|:3
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x=12-y
y=0,25
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x= 12-0,25
y= 0,25
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x= 11,75
y=0,25