①(x+3y)^2(x-3y)^2

学习时间:2026-10-03 11:43:43 阅读：3383

①(x+3y)^2(x-3y)^2②(0.5m+n)(0.5m-n)(0.25m^2-n^2)小数为分数（分数不好打）

英俊的芒果

2026-10-03 11:43:43

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①(x+3y)^2(x-3y)^2=（(x+3y)(x-3y)）^2=(x^2-9y^2)^2=x^4+81y^4-18x^2y^2②(0。5m+n)(0。5m-n)(0。25m^2-n^2)=(0。25m^2-n^2)(0。25m^2-n^2)=0。625m^4-0。5m^2n^2+n^4