已知m,x,y满足:(1)(x-5)²+|m|=0,(2)﹣2ab的y+1次方与4ab³是同类项.求代数式:(2x²-3xy+6y²)-m(3x²-xy+9y²)的值.
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/25 17:26:54
![已知m,x,y满足:(1)(x-5)²+|m|=0,(2)﹣2ab的y+1次方与4ab³是同类项.求代数式:(2x²-3xy+6y²)-m(3x²-xy+9y²)的值.](/uploads/image/z/1107054-54-4.jpg?t=%E5%B7%B2%E7%9F%A5m%2Cx%2Cy%E6%BB%A1%E8%B6%B3%3A%EF%BC%881%EF%BC%89%EF%BC%88x%EF%BC%8D5%EF%BC%89%26%23178%3B%2B%7Cm%7C%EF%BC%9D0%2C%EF%BC%882%EF%BC%89%EF%B9%A32ab%E7%9A%84y%EF%BC%8B1%E6%AC%A1%E6%96%B9%E4%B8%8E4ab%26%23179%3B%E6%98%AF%E5%90%8C%E7%B1%BB%E9%A1%B9.%E6%B1%82%E4%BB%A3%E6%95%B0%E5%BC%8F%EF%BC%9A%EF%BC%882x%26%23178%3B%EF%BC%8D3xy%2B6y%26%23178%3B%EF%BC%89%EF%BC%8Dm%EF%BC%883x%26%23178%3B%EF%BC%8Dxy%2B9y%26%23178%3B%EF%BC%89%E7%9A%84%E5%80%BC.)
已知m,x,y满足:(1)(x-5)²+|m|=0,(2)﹣2ab的y+1次方与4ab³是同类项.求代数式:(2x²-3xy+6y²)-m(3x²-xy+9y²)的值.
已知m,x,y满足:(1)(x-5)²+|m|=0,(2)﹣2ab的y+1次方与4ab³是同类项.求代数式:(2x²-3xy+6y²)-m(3x²-xy+9y²)的值.
已知m,x,y满足:(1)(x-5)²+|m|=0,(2)﹣2ab的y+1次方与4ab³是同类项.求代数式:(2x²-3xy+6y²)-m(3x²-xy+9y²)的值.
由题意得,x=5,m=0,y=2
所以原式=2x²-3xy+6y²
=2*25-3*5*2+6*4
=50-30+24
=44
由(x-5)²+|m|=0,得x=5, m=0
由-2ab^(y+1)与4ab³是同类项,得y+1=3,y=2
代入(2x²-3xy+6y²)-m(3x²-xy+9y²)
2*25-3*5*2+6*4
=44
(x-5)²+|m|=0则x=5,m=0
﹣2ab的y+1次方与4ab³是同类项,则y+1=3,y=2
代入式子即可
(x-5)²+|m|=0
则x=5,m=0
2ab^y+1与4ab³同类项
则y+1=3,y=2
(2x²-3xy+6y²)-m(3x²-xy+9y²)(即知m=0,后项不管)
=2x²-3xy+6y²
当x=5,y=2时
=2×5²-3×5×2+6×2...
全部展开
(x-5)²+|m|=0
则x=5,m=0
2ab^y+1与4ab³同类项
则y+1=3,y=2
(2x²-3xy+6y²)-m(3x²-xy+9y²)(即知m=0,后项不管)
=2x²-3xy+6y²
当x=5,y=2时
=2×5²-3×5×2+6×2²
=50-30+24
=44
不懂可追问!
收起