Expand (y-1)^2 Then expand (2x+y-1)^2 Thx?
回答 (2)
2016-10-31 12:12 pm
(y-1)^2=y^2-2y+1
(2x+y-1)^2=(2x)^2+2(2x)(y-1)+(y-1)^2
=4x^2+4xy-4x+y^2-2y+1
(2x+y-1)^2=(2x)^2+2(2x)(y-1)+(y-1)^2
=4x^2+4xy-4x+y^2-2y+1
2016-10-30 9:50 am
Sol
(y－1)^2=y^2－2y+1
(2x+y－1)^2
=[(2x+y)－1]^2
=(2x+y)^2－2(2x+y)+1
=(4x^2+4xy+y^2)－(4x+2y)+1
=4x^2+y^2+1+4xy－4x－2y+1
(y－1)^2=y^2－2y+1
(2x+y－1)^2
=[(2x+y)－1]^2
=(2x+y)^2－2(2x+y)+1
=(4x^2+4xy+y^2)－(4x+2y)+1
=4x^2+y^2+1+4xy－4x－2y+1
收錄日期: 2021-04-18 15:45:15
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20161030013127AANQtl0