简便123²-122×124 ﹙2a-1﹚²-4﹙a-1﹚﹙a+1﹚ 今天就要
来源:学生作业帮 编辑:神马作文网作业帮 分类:数学作业 时间:2024/09/30 20:27:29
简便123²-122×124 ﹙2a-1﹚²-4﹙a-1﹚﹙a+1﹚ 今天就要
123²-122×124
=123²-(123-1)(123+1)
=123²-(123²-1)
=123²-123²+1
=1
﹙2a-1﹚²-4﹙a-1﹚﹙a+1﹚
=(4a²-4a+1)-4(a²-1)
=4a²-4a+1-4a²+4
=-4a+5
再问: ﹙2/3ab²﹚×﹙-2a﹚³ 1+﹙-½﹚负二的平方-﹙3.14-π)
再答: ﹙2/3ab²﹚×﹙-2a﹚³ =2/3ab²×(-8a³ ) =-16a²/3b² 1+﹙-½﹚负二的平方-﹙3.14-π) =1+﹙-½﹚×4-3.14+π =1-2-3.14+π =π-4.14
再问: (2a-b)²+(a+1-b)(a+1+b)-(a+1)²
再答: (2a-b)²+(a+1-b)(a+1+b)-(a+1)² =(2a-b)²+[(a+1)²-b²]-(a+1)² =(2a-b)²-b² =(2a-b+b)(2a-b-b) =2a(2a-2b) =4a²-4ab
=123²-(123-1)(123+1)
=123²-(123²-1)
=123²-123²+1
=1
﹙2a-1﹚²-4﹙a-1﹚﹙a+1﹚
=(4a²-4a+1)-4(a²-1)
=4a²-4a+1-4a²+4
=-4a+5
再问: ﹙2/3ab²﹚×﹙-2a﹚³ 1+﹙-½﹚负二的平方-﹙3.14-π)
再答: ﹙2/3ab²﹚×﹙-2a﹚³ =2/3ab²×(-8a³ ) =-16a²/3b² 1+﹙-½﹚负二的平方-﹙3.14-π) =1+﹙-½﹚×4-3.14+π =1-2-3.14+π =π-4.14
再问: (2a-b)²+(a+1-b)(a+1+b)-(a+1)²
再答: (2a-b)²+(a+1-b)(a+1+b)-(a+1)² =(2a-b)²+[(a+1)²-b²]-(a+1)² =(2a-b)²-b² =(2a-b+b)(2a-b-b) =2a(2a-2b) =4a²-4ab
简便123²-122×124 ﹙2a-1﹚²-4﹙a-1﹚﹙a+1﹚ 今天就要
用简便方法计算:3﹙a-2b﹚﹙1/3a+2/3b﹚.
先化简,在求值.a﹙3-a﹚²+2a²﹙a+1﹚-3a﹙2a-5b+1﹚,其中a=-1,b=2.
(1)用简便方法计算:2014²-2013×4028+2013²;(2)若100﹙a-b﹚²
(a-1)(a^99+a^98+a^97+……+a^2+a+1)简便方法!
【1】a+a=a×a a= [ ]【2】a×a=a÷a a=[ ]【3】a×a=a-a a=[ ] [4]a-a=a+a
a³÷1/a×a+﹙﹣a²﹚³+﹙﹣a³﹚²﹣a²×a
﹙a²+b²-1﹚²-4a²b²
已知|2a-b+1|+(3a+3/2b²=0,求b²/(a+b)÷[﹙a/(a-b)-1﹚﹙a-a&
a²-4/a²+2a-8﹢﹙a²-4﹚×a²-4a+4/a-2怎么解?
(a+2b)(a-2b)﹙a²-4b²﹚.
若﹙a-1/a﹚=15,则a²+1/a²=?