3x+y/2=7x+3y=1/2,则x=?y=?
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3x+y/2=7x+3y=1/2,则x=?y=?
3x+y/2=7x+3y=1/2,则x=?y=?
3x+y/2=7x+3y=1/2,则x=?y=?
由题意:3x+y/2=1/2 (1),7x+3y=1/2(2)
(1)两边同乘以2,得:6x+y=1(3)
(2)两边同乘以2,得:14x+6y=1(4)
(3)两边同乘以6,再减去(4),得:36x+6y-14x-6y=6-1
22x=5
x=5/22
带入(3),得:y=1-30/22
=-4/11
3x+y/2=1/2 ,7x+3y=1/2
两式同乘以2,得:6x+y=1 (1) ,14x+6y=1 (2)
由(1)式得:y=1-6x (3)
将(3)式代入(2)式:14x+6(1-6x)=1
得 :x=5/22
将x代入(1)式得:
6(5/22)+y=1
y=-4/11
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