计算:(1)[(X-Y)^2-(X+Y)(X-Y)]/(-2Y) (2)(2a+1)^2-(2a+1)(2a-1) (3

计算:(1)[(X-Y)^2-(X+Y)(X-Y)]/(-2Y) (2)(2a+1)^2-(2a+1)(2a-1) (3)(2x-y-3)(2x-y+3)
love-benny 1年前 已收到1个回答 举报
赞

811126 花朵

共回答了19个问题采纳率：89.5% 举报

(1)[(X-Y)^2-(X+Y)(X-Y)]/(-2Y)
=[(x^2-2xy+y^2)-(x^2-y^2)]/(-2y)
=[x^2-2xy+y^2-x^2+y^2]/(-2y)
=(2y^2-2xy)/(-2y)
=x-y
(2)(2a+1)^2-(2a+1)(2a-1)
=(4a^2+4a+1)-4a^2+1
=4a+2
(3)(2x-y-3)(2x-y+3)
=[(2x-y)-3][(2x-y)+3]
=(2x-y)^2-9
=4x^2-4xy+y^2-9

1年前

8
可能相似的问题

你能帮帮他们吗

精彩回答

Copyright © 2024 YULUCN.COM - 雨露学习互助 - 17 q. 0.040 s. - webmaster@yulucn.com