x³+y³=(x+y)(x²-xy+y²)=(x+y)(x²+2xy+y²-3xy)=(x+y)((x+y)²-3xy)=(-3)·((-3)²-3·(-5))=-72
Теперь надо решить квадратное уравнение:
y^{2}+3y-5=0
Δ=3²-4*1*(-5)=9+20=29
y1=
y2=
x1=-5:=====-=-
x2=-5:=====-
Получается y1=x2, y2=y1
x³+y³=(-)³+(-)³
x³+y³=
x³+y³=-72
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Verified answer
x³+y³=(x+y)(x²-xy+y²)=(x+y)(x²+2xy+y²-3xy)=(x+y)((x+y)²-3xy)=(-3)·((-3)²-3·(-5))=-72
Verified answer
Теперь надо решить квадратное уравнение:
y^{2}+3y-5=0
Δ=3²-4*1*(-5)=9+20=29
y1=
y2=
x1=-5:
=
=
=
=
=-
=-
x2=-5:
=
=
=
=
=-
Получается y1=x2, y2=y1
x³+y³=(-
)³+(-
)³
x³+y³=
x³+y³=
x³+y³=
x³+y³=
x³+y³=-72