Помогите решить систему

x^3-y^3=98

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xy^2-yx^2=-30

X^3-y^3=98

xy^2-yx^2=-30

(x-y) (x^2+xy+y^2) = 98

xy (y-x) = - 30

xy (x-y) = 30

x-y=30/xy

(30/xy) (x^2+xy+y^2) = 98

30 (x ^ 2+xy+y ^ 2) = 98xy

30x ^2-68xy+30y ^ 2=0 y0

30x ^ 2/y ^ 2 - 68xy/y ^ 2+30=0

(x/y) = a

30a ^ 2-68a+30=0

15a ^ 2-34a+15=0

d=34 ^ 2-4*15*15=256=16 ^ 2

a1=5/3

a2=3/5

1) x/y=5/3

x=5y/3

(5y/3) ^ 3-y ^ 3=98

(125y ^ 3-27y ^ 3) / 27=98

98y ^3 / 27=98

y ^3/27=1

y ^ 3=27

y=3 = > x=5

2) x/y=3/5

x=3y/5

(3y/5) ^3-y ^ 3=98

27y ^ 3/125 y ^3=98

(27y ^ 3-125y ^ 3) / 125=98

-98y ^ 3/125=98

-y ^ 3/125=1

y ^ 3=-125

y=-5 = > x = - 3