先化简,再求值:(a 2)²-(1-a)(-a-1),其中a=
来源:学生作业帮助网 编辑:作业帮 时间:2024/05/31 23:07:55
(a"-1)/(a-1)-√(a"+2a+1)/(a"+a)-1/a=[(a"-1")/(a-1)]-[√(a+1)"/(a+1)a]-1/a注意,开方之后必须是正数=[(a+1)(a-1)/(a-1
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
∵a2+ab-2b2=0∴(a+2b)(a-b)=0∴a=-2b或者a=b原式=(a²-b²-a²-b²)/ab=-2b²/ab=-2b/a当a=-2
因为化简后算式变为常数4,结果与x的取值无关,所以不管x等于多少,这道题的计算结果都为4
(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)=
很简单,a²-1/a²-2a+1=(a+1)(a-1)/(a-1)²a+1/a3-a²=a+1/a²(a-1)原式==(a+1)(a-1)/(a-1)
原式=(a-b)²/(a+b)(a-b)÷(b-a)/ab=(a-b)/(a+b)×[-ab/(a-b)]=-ab/(a+b)=-(2-1)/(2√2)=-√2/4
原式=4a2-3a+2+4a-a2-2a2-a+1=a2+3,当a=-2时,原式=4+3=7.
解题思路:根据平方差公式求解解题过程:varSWOC={};SWOC.tip=false;try{SWOCX2.OpenFile("http://dayi.prcedu.com/include/rea
原式=3a2-ab+7-5ab-4a2+7,=-a2-6ab+14,把a=-2,b=13代入上式得:原式=-a2-6ab+14=-(-2)2-6×(-2)×13+14=14.
(2x²y-2xy²)-[(-3x²y²+3x²y)+(3x²y²-3xy²)]=2x²y-2xy²
[(4-a^2)/(a^2+6a+9)]÷[(a-2)/(2a+6)]+2=[(2-a)(2+a)/(a+3)^2]÷[(a-2)/(2a+6)]+2=(2-a)(2+a)/(a+3)^2*(2a+6
题目是这个吧:(4-a)/(a+6a+9)÷(a-2)/(2a+6)+2(4-a)/(a+6a+9)÷(a-2)/(2a+6)+2=-(a+2)(a-2)/(a+3)÷(a-2)/2(a+3)+2=-
原式=4a4a2+64a88a6=4a2+8a2=12a2∵a=-2,∴原式=12×(-2)2=12×4=48.
原式=-10a2-6a+6,将a=-2代入原式得:原式=-10a2-6a+6=-10×(-2)2-6×(-2)+6=-22.
原式=a2-b2+2a2=3a2-b2,当a=1,b=2时,原式=3-4=-1.
原式=4a+3a2-3-3a3+a-4a3=-7a3+3a2+5a-3,当a=-2时,原式=56+12-10-3=55.