Решите системух^2+ху=1у-3х=7

Question

Решите систему
х^2+ху=1
у-3х=7

Answer 1

Х^2+xy=2 x(x-y)=2 x^2+3x^2+7x-2=0 y-3x=7 y=3x+7 y=3x+7 x^2+3x^2+7x-2=0 4x^2+7x-2=0 D=b^2-4ac D=49-4*4*(-2)=49+32=81 x1=(-7+9)\8=1\4 x2=(-7-9)\8=-2 x1=1\4 x2=-2

Comments

х^2+xy=2 x(x-y)=2 x^2+3x^2+7x-2=0
y-3x=7 y=3x+7 y=3x+7
x^2+3x^2+7x-2=0
4x^2+7x-2=0
D=b^2-4ac
D=49-4*4*(-2)=49+32=81
x1=(-7+9)\8=1\4
x2=(-7-9)\8=-2
x1=1\4 x2=-2

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y=3(-2)+7

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y2=-6+7=1

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y1=3(1\4)+7=7 3\4