几道初一数学题,各位大哥大姐帮帮忙~1.若-2是m的立方根,则m²+m=_2.已知三次根号(y-1)与三次根号(1-2x)互为相反数,则x/y的值是_3.解方程组{x+y-z=11,y+z-x=5,z+x-y=1,则x=_,y=_,z=_4.若x=2y+3z=1
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![几道初一数学题,各位大哥大姐帮帮忙~1.若-2是m的立方根,则m²+m=_2.已知三次根号(y-1)与三次根号(1-2x)互为相反数,则x/y的值是_3.解方程组{x+y-z=11,y+z-x=5,z+x-y=1,则x=_,y=_,z=_4.若x=2y+3z=1](/uploads/image/z/10143566-62-6.jpg?t=%E5%87%A0%E9%81%93%E5%88%9D%E4%B8%80%E6%95%B0%E5%AD%A6%E9%A2%98%2C%E5%90%84%E4%BD%8D%E5%A4%A7%E5%93%A5%E5%A4%A7%E5%A7%90%E5%B8%AE%E5%B8%AE%E5%BF%99%7E1.%E8%8B%A5-2%E6%98%AFm%E7%9A%84%E7%AB%8B%E6%96%B9%E6%A0%B9%2C%E5%88%99m%26%23178%3B%2Bm%3D%EF%BC%BF2.%E5%B7%B2%E7%9F%A5%E4%B8%89%E6%AC%A1%E6%A0%B9%E5%8F%B7%EF%BC%88y-1%29%E4%B8%8E%E4%B8%89%E6%AC%A1%E6%A0%B9%E5%8F%B7%EF%BC%881-2x%EF%BC%89%E4%BA%92%E4%B8%BA%E7%9B%B8%E5%8F%8D%E6%95%B0%2C%E5%88%99x%2Fy%E7%9A%84%E5%80%BC%E6%98%AF%EF%BC%BF3.%E8%A7%A3%E6%96%B9%E7%A8%8B%E7%BB%84%7Bx%2By-z%3D11%2Cy%2Bz-x%3D5%2Cz%2Bx-y%3D1%2C%E5%88%99x%3D%EF%BC%BF%2Cy%3D%EF%BC%BF%2Cz%3D%EF%BC%BF4.%E8%8B%A5x%3D2y%2B3z%3D1)
几道初一数学题,各位大哥大姐帮帮忙~1.若-2是m的立方根,则m²+m=_2.已知三次根号(y-1)与三次根号(1-2x)互为相反数,则x/y的值是_3.解方程组{x+y-z=11,y+z-x=5,z+x-y=1,则x=_,y=_,z=_4.若x=2y+3z=1
几道初一数学题,各位大哥大姐帮帮忙~
1.若-2是m的立方根,则m²+m=_
2.已知三次根号(y-1)与三次根号(1-2x)互为相反数,则x/y的值是_
3.解方程组{x+y-z=11,y+z-x=5,z+x-y=1,则x=_,y=_,z=_
4.若x=2y+3z=10,4x+3y+2z=15,则x+y+z的值为_
A.2 B.3 C.4 D.5
几道初一数学题,各位大哥大姐帮帮忙~1.若-2是m的立方根,则m²+m=_2.已知三次根号(y-1)与三次根号(1-2x)互为相反数,则x/y的值是_3.解方程组{x+y-z=11,y+z-x=5,z+x-y=1,则x=_,y=_,z=_4.若x=2y+3z=1
1.m=-8,m²+m=56
2.y-1=-(1-2x)
y-1=2x-1
y=2x
x/y=1/2
3.x+y-11=z,代入后面两式:
y+x+y-11-x=5,2y=16,y=8
x+y-11+x-y=1,2x=12,x=6
6+8-11=z,z=3
4.x=10
2y+3z=10,————(1)
40+3y+2z=15,3y+2z=-25—————(2)
由(1)(2)得:
2y=10-3z,y=5-3/2z
15-9/2z+2z=-25
-5/2z=-40
z=16
y=5-24=-19
X+y+z=10-19+16=7
第一题:3^2/3-2^1/3,第二题:1/2,第三题:x=6,y=8,z=3第四题:选D