m为何值时,二元一次方程组2x+y=5m,2x-y=7m的解满足方程1/3x-2y=5
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![m为何值时,二元一次方程组2x+y=5m,2x-y=7m的解满足方程1/3x-2y=5](/uploads/image/z/581537-65-7.jpg?t=m%E4%B8%BA%E4%BD%95%E5%80%BC%E6%97%B6%2C%E4%BA%8C%E5%85%83%E4%B8%80%E6%AC%A1%E6%96%B9%E7%A8%8B%E7%BB%842x%2By%3D5m%2C2x-y%3D7m%E7%9A%84%E8%A7%A3%E6%BB%A1%E8%B6%B3%E6%96%B9%E7%A8%8B1%2F3x-2y%3D5)
m为何值时,二元一次方程组2x+y=5m,2x-y=7m的解满足方程1/3x-2y=5
m为何值时,二元一次方程组2x+y=5m,2x-y=7m的解满足方程1/3x-2y=5
m为何值时,二元一次方程组2x+y=5m,2x-y=7m的解满足方程1/3x-2y=5
两式相加得,4x = 12m,x = 3m
两式相减得,2y = -2m,y = -m
因为满足方程x/3 - 2y = 5
代入得,m + 2m = 5,所以m = 5/3
2x+y=5m(1)
2x-y=7m(2)
(1)+(2)得4x=12m x=3m
(1)-(2)得2y= -2m y= -m
将 x=3m y= -m代入1/3x-2y=5得 1/3*3m-2*(-m)=5
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2x+y=5m(1)
2x-y=7m(2)
(1)+(2)得4x=12m x=3m
(1)-(2)得2y= -2m y= -m
将 x=3m y= -m代入1/3x-2y=5得 1/3*3m-2*(-m)=5
m+2m=5
3m=5
m=5/3
m=5/3时,二元一次方程组2x+y=5m,2x-y=7m的解满足方程1/3x-2y=5
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2x+y+2x-y=12m 4x=12m x=3m
2x+y-(2x-y)=-2m 2y=-2m 那么原方程化为 :m+2m=5 m=5/3 给个好评吧!