由题,x+2y=3,2y-x=-7,两式相加得4y=-4,所以y=-1,x=5
3x+5y-(x+y)=6 2(x+y)-3x=-7
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相关问题
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- {5x-2y=3{x+6y=7- {x+2y=0{3x+4y-6=0- {x-y=5{2x=15-3y- {3x-2
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2x-3y-2=0 5x+3y=18 2x-3y=7 (2x-3y+5)/7+2y=9 2x-3y=3 6x+5y=35
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1、(2x+3y)(3x-5y)-(x+y)(6x-7y)
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送分的5x+y=7,3x-y=1 4x-3y=5,4x+6y=14 6x+7y=5,6x-7y=190.5x-3y=-1
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求解(1){2x-y=9 3x+y=7 (2){4x-3y=5.6 5x+3y=7.4 (3){2x+3y+19=0 x
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(1)7x+3y=18 2x+3y=13 (2)5x+2y=7 2x+y=1 (3)3x+4y=5 4x+5y=6如题
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5x-2y=3 x+6y=7
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{y=3x-7{5x+2y=8{x-2y=3{2y+x=-1{2y-x=6{2x+y=8
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8y-(8-5y)=3y+2(4y+7) 8-3y=6-x 4x-3(20-x)=5x-7(20-
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解方程(1) {5x+2y=2 7x-5y=34 (2){8x+3y+2=0,6x+5y+7=0 (3){x+1/3-y