真的就这样了么
幼苗
共回答了469个问题 举报
4/9x^2-0.01n^2=(2/3x-0.1n)(2/3x+0.1n)
①x^2+2x+1=(x+1)^2 x^2-2x+1=(x-1)^2
②1-6y+9y^2
=9y^2-6y+1
=(3y-1)^2
③4a^2+4a+1=(2a+1)^2
④1+m+m^2/4
=(m/2)^2+m+1
=(m/2+1)^2
⑤25x^4+10x^2+1=(5x^2+1)^2
⑥-x^2-4y^2-4xy
=-(x^2+4xy+4y^2)
=-(x+2y)^2
1年前
1