若(x²+nx+3)(x²-3x+m)的乘积中不含x²和x³项,求m,n的值
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![若(x²+nx+3)(x²-3x+m)的乘积中不含x²和x³项,求m,n的值](/uploads/image/z/1988744-32-4.jpg?t=%E8%8B%A5%EF%BC%88x%26%23178%3B%2Bnx%2B3%29%28x%26%23178%3B-3x%2Bm%29%E7%9A%84%E4%B9%98%E7%A7%AF%E4%B8%AD%E4%B8%8D%E5%90%ABx%26%23178%3B%E5%92%8Cx%26%23179%3B%E9%A1%B9%2C%E6%B1%82m%2Cn%E7%9A%84%E5%80%BC)
若(x²+nx+3)(x²-3x+m)的乘积中不含x²和x³项,求m,n的值
若(x²+nx+3)(x²-3x+m)的乘积中不含x²和x³项,求m,n的值
若(x²+nx+3)(x²-3x+m)的乘积中不含x²和x³项,求m,n的值
(x²+nx+3)(x²-3x+m)
=x⁴-3x³+mx²+nx³-3nx²+mnx+3x²-9x+3m
=x⁴+(n-3)x³+(m-3n+3)x²+(mn-9)x+3m
∵乘积中不含x²和x³项
∴n-3=0且m-3n+3=0
∴n=3,m=6