先化简后求值a-1 a 2乘以a²-2a 1 a²-4 1 a²-1
来源:学生作业帮助网 编辑:作业帮 时间:2024/05/09 03:09:27
原式=3a/(a-1)*(a+1)(a-1)/a-a(a+1)*(a+1)(a-1)/a=3(a+1)-(a-1)=3a+3-a+1=2a+4当a=√2-2时,原式=2*(√2-2)+4=2√2答:所
∵a=2-√3,∴1-a=√3-1>0a-1分之1-2a+a2-a分之根号a2-2a+1-a分之1=(a-1)^2/(a-1)-(1-a)/a-1/a=a-1-1/a+1-1/a=a-2/a=2-√3
=[(a²-4)/(a-2)]×1/a(a+2)=[(a+2)(a-2)/(a-2)]×1/a(a+2)=(a+2)×1/a(a+2)=1/a
.(a-1分之3a剪a+1分之a)乘以a分之a²剪1=[3a/(a-1)-a/(a+1)]×(a+1)(a-1)/a=3a/(a-1)×(a+1)(a-1)/a-a/(a+1)×(a+1)(
原式=2-a2+4a-5a2+a+1=-6a2+5a+3,当a=-2时,原式=-6×4+5×(-2)+3=-31.
(2a+6)/(a2-4a+4)×(a-2)/(a2+3a)-(1/a-2)=2(a+3)/(a-2)²×(a-2)/[a(a+3)]-1/(a-2)=2/[a(a-2)]-1/(a-2)=
原式=4a2-3a+2+4a-a2-2a2-a+1=a2+3,当a=-2时,原式=4+3=7.
5a2+3b2+2(a2-b2)-(5a2-3b2)=5a2+3b2+2a2-2b2-5a2+3b2=2a2+4b2,把a=-1,b=12代入得:2a2+4b2=2+1=3.
[(a^2-4)/(a^2-4a+4)+1/(2-a)]÷2/(a^2-2a)=[(a+2)(a-2)/(a-2)^2-1/(a-2)]乘a(a-2)/2=[(a+2)/(a-2)-1/(a-2)]乘
具体步骤应为:原式=(a²-5a+2/a+2+a+2/a+2)÷[(a+2)(a-2)/(a+2)²]=(a²-4a+4/a+2)×(a+2)²/(a+2)(a
2a+1/a2-1×a2-2a+1/a2-a-1/a+1=2/a²-a-1/a+1=(2+a²-a)/a²-a=(2+a²-a-a³)/a²
原式=[(a²-1)/(a²-2a+1)]+[(2a-a²)/(a-2)]÷a=[(a+1)(a-1)/(a-1)²]+[-a(a-2)/(a-2)]×(1/a
解原式=[(a+2)/a²]÷[(a²-4)/a]=(a+2)/a²×a/(a-2)(a+2)=1/a(a-2)=1/(√3)(√3-2)=1/(3-2√3)=(3+2√
原式=(a2-b2-a2+2ab-b2)÷2b=(-2b2+2ab)÷2b=-b+a,∵a2+2a+1+|b-12|=(a+1)2+|b-12|=0,∴a+1=0,b-12=0,即a=-1,b=12,
不好意思再答:看错了再问:,,提负号有问题吧,,再答:对的呀再问:谢了再答:不客气
原式=a2-b2+2a2=3a2-b2,当a=1,b=2时,原式=3-4=-1.
[(a-2)/(a^2+2a)-(a-1)/(a^2+4a+4)]÷(a-4)/(a+2)=[(a-2)/a(a+2)-(a-1)/(a+2)^2]÷(a-4)/(a+2)=[(a-2)/a(a+2)
1、4A²-4AB+B²=(2A-B)²2、原式=5A+AB-3A==2A+AB=2×4+4×(-1)=8-4=4
原式=6a-2-6+15a-9a2=21a-9a2-8,把a=-13代入,原式=21×(-13)-9×(-13)2-8=-7-1-8=-16.