Question

9(x-y)的平方-6(x-y)+1？

Answer 1

9(x-y)的平方-6(x-y)+1
=[3(x-y)-1]²
=（3x-3y-1）²
如果本题有什么不明白可以追问,,4,9(x-y)的平方-6(x-y)+1
=[3(x-y)-1]^2
=(3x-3y-1)^2,2,