1)x=3, y=4
2)x=-3, y=-4
3)x=-4,y=-3
4)x=4, y=3
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x²+y²=25
xy=12
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x²+2xy +y²=(x+y)²
(x²+y²)+2xy=(x+y)²
25+24=(x+y)²
(x+y)²=49
x+y=7 ili x+y=-7
a)x=7-y, (7-y)²+y²=25, 49-14y+2y²=25,2y²-14y+24=0 , y²-7y+12=0
(y-3)(y-4)=0 , y=3, y=4
y=3,x=4 ili y=4, x=3
b)x=-7-y, (-7-y)²+y²=25, 49+14y+2y²=25, 2y²+14y+24=0, y²+7y+12=0
(y+3)(y+4)=0, y=-3, y=-4
y=-3,x=-4 ili y=-4,x=-3