qintianhao200858
幼苗
共回答了12个问题采纳率:91.7% 举报
(1) 27a^6 -12a^6 = 15a^6
(2) (x - 2y + 3)(x + 2y - 3)
=[x - (2y -3)][ x + (2y-3)]
= x² -(2y - 3)²
= x² - 4y²+ 12y -9
1年前
追问
7
玉之利
举报
(3a²)³-6a³(2a³+3a²+a)=
举报
qintianhao200858
(3a²)³-6a³(2a³+3a²+a) =27a^6 -12a^6 - 18a^5 - 6a^4 = 15a^6 - 18a^5 - 6a^4