Question

решить систему уравнений x^3-y^3=56 и x^2+xy+y^2=28

Answer 1

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Answer 2

1)x³-y³=56
x²+xy+y²=28
2)    |(x-y)(x²+xy+y²)=56
    ÷ |x²+xy+y²=28
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(x-y)(x²+xy+y²)/x²+xy+y²=56/28
x-y=2
x=2+y
3) x=2+y
(2+y)³-y³=56
(2+y-y)[(2+y)²+(2+y)y+y²)=56
4+4y+y²+2y+y²+y²=28
3y²+6y-24=0
y²+2y-12=0
k=1
D=1+24=25
y1=-6  y2=4
4)y=-6
x=2-6=-4

y=4
x=2-4=-2
ответ:(-4;-6);(-2;4)