小马过河-0
幼苗
共回答了17个问题采纳率:100% 举报
1.49(a-b)方-16(a+b)方
=(7(a-b)+4(a+b))(7(a-b)-4(a+b))
=(11a-3b)(3a-11b)
2.(2x+y)方-(x+2y)方
=[(2x+y)+(x+2y)][(2x+y)-(x+2y)]
=(3x+3y)(x-y)
=3(x+y)(x-y)
=3x^2-3y^2
3.(x²+y²)²-x²y²
=(x^2+y^2+xy)(x^2+y^2-xy)
4.(m+n)²-n²
=(m+n+n)(m+n-n)
=(m+2n)m
5.3ax²-3ay的四次方
=3a(x^2-y^4)
=3a(x+y^2)(x-y^2)
1年前
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