已知多项式(2mx²=5x²+3x+1)-(7x²-4y²+3x)化简后不含x²项.(1)求m的值;(2)求多项式2m³-[3m³-(4m-5)+m]的值.
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![已知多项式(2mx²=5x²+3x+1)-(7x²-4y²+3x)化简后不含x²项.(1)求m的值;(2)求多项式2m³-[3m³-(4m-5)+m]的值.](/uploads/image/z/402012-36-2.jpg?t=%E5%B7%B2%E7%9F%A5%E5%A4%9A%E9%A1%B9%E5%BC%8F%EF%BC%882mx%26%23178%3B%3D5x%26%23178%3B%2B3x%2B1%EF%BC%89-%EF%BC%887x%26%23178%3B-4y%26%23178%3B%2B3x%EF%BC%89%E5%8C%96%E7%AE%80%E5%90%8E%E4%B8%8D%E5%90%ABx%26%23178%3B%E9%A1%B9.%EF%BC%881%EF%BC%89%E6%B1%82m%E7%9A%84%E5%80%BC%EF%BC%9B%EF%BC%882%EF%BC%89%E6%B1%82%E5%A4%9A%E9%A1%B9%E5%BC%8F2m%26%23179%3B-%5B3m%26%23179%3B-%EF%BC%884m-5%EF%BC%89%2Bm%5D%E7%9A%84%E5%80%BC.)
已知多项式(2mx²=5x²+3x+1)-(7x²-4y²+3x)化简后不含x²项.(1)求m的值;(2)求多项式2m³-[3m³-(4m-5)+m]的值.
已知多项式(2mx²=5x²+3x+1)-(7x²-4y²+3x)化简后不含x²项.
(1)求m的值;
(2)求多项式2m³-[3m³-(4m-5)+m]的值.
已知多项式(2mx²=5x²+3x+1)-(7x²-4y²+3x)化简后不含x²项.(1)求m的值;(2)求多项式2m³-[3m³-(4m-5)+m]的值.
原题是2mx²=(5x²+3x+1)-(7x²-4y²+3x)?还是(2mx²-5x²+3x+1)-(7x²-4y²+3x)?
前面一种情况m=-1,多项式=-7
后面一种情况是m=6,多项式=-216+21-6=-201
(2mx²+5x²+3x+1)-(7x²-4y²+3x)
=(2m+5-7)x²+1+4y²
∵不含有x²项
∴2m+5-7=0
∴m=1
∴2m³-[3m³-(4m-5)+m]
=-m³+3m-5
=1-3-5
=-7