3Х - Y = - 10
3X + 10 = Y
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Y^2 = 9X^2 + 60X + 100
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X^2 - 4XY - Y^2 = - 20
X^2 - 4X*( 3X + 10) - ( 9X^2 + 60X + 100) = - 20
X^2 - 12X^2 - 40X - 9X^2 - 60X - 100 + 20 = 0
- 20X^2 - 100X - 80 = 0
- 20 * ( X^2 + 5X + 4 ) = 0
D = 25 - 16 = 9 ; V D = 3
X1 = ( - 5 + 3 ) : 2 = ( - 1 )
X2 = ( - 8 ) : 2 = ( - 4 )
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Y = 3X + 10
Y1 = - 3 + 10 = 7
Y2 = - 12 + 10 = ( - 2 )
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Ответ ( - 1 ; 7 ) ; ( - 4 ; - 2 )
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Y = X - 1
Y = X^2 + 2X - 3
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X^2 + 2X - 3 = X - 1
X^2 + X - 2 = 0
D = 1 - 4*1*(-2) = 9 ; V D = 3
X1 = ( - 1 + 3 ) : 2 = 1
X2 = ( - 4 ) : 2 = ( - 2 )
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Y = X - 1
Y1 = 1 - 1 = 0
Y2 = - 2 - 1 = ( - 3 )
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ответ ( 1 ; 0 ) ; ( - 2 ; - 3 )