12. 若 5x 2 与 −2x 9 互为相反数,则 x−2 的值为
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1x2/2x3=32x4/4x6=33x6/6x9=34x8/8x12=3所以原式=3
由已知可得a=-1/2,b=3,所以a/b=-1/2×1/3=-1/6
不对!
根据题意得:2x-5+17-3(x-2)=0,去括号得:2x-5+17-3x+6=0,移项合并得:-x=-18,解得:x=18,则x2-x=324-18=306.
∵x2+4x-5与2-2x是互为相反数,∴x2+4x-5+2-2x=0,∴x2+2x-3=0,∴(x-1)(x+3)=0,解得x=-3或x=1.故答案为-3或1.
1x2+2x4+3x6+4x8=(1x2)(1+2+3+4)2x3+4x6+6x9+8x12=(2x3)(1+2+3+4)所以,(1x2+2x4+3x6+4x8)/(2x3+4x6+6x9+8x12)
要过程吗?再问:给答案就可以了朋友再答:6。461即84/13
∵|x-y+1|与x2+8x+16互为相反数,∴|x-y+1|与(x+4)2互为相反数,即|x-y+1|+(x+4)2=0,∴x-y+1=0,x+4=0,解得x=-4,y=-3.当x=-4,y=-3时
53/582再问:怎么算的啊?再答:x7=85/6x1+x2.....+x10=971/685/6/971/6=53/582
令y=2-x,则-x=log2y,∴x=-log2y,∴g(x)的反函数:f(x)=-log2x,则f(3+2x-x2)=-log2(3+2x−x2),由3+2x-x2>0,得-1<x<3,∴f(3+
∵2x2+1与4x2-2x-5互为相反数,∴2x2+1+4x2-2x-5=0,∴3x2-x-2=0,即(x-1)(3x+2)=0,x-1=0或3x+2=0,解得x1=1,x2=-23.
由题意:x1,x2,…,x9均为正整数,得x1最小值为1,∵当x1,x2,…,x8取到最小值时,x9取到最大值=220-(1+2+3+…+8)=220-36=184,∴又∵1+2+3+…+9=45,2
n+(0123到n-1)*9=(11111..)n个1
1/1x2+1/2x3+1/3x4+1/4x5+1/5x6+1/6x7+1/7x8+1/8x9+1/9x10=1-1/2+1/2-1/3+1/3-.-1/9+1/9-1/10=1-1/10=9/10再
由题意可得|m+4|+(n-1)2=0,∴m+4=0n−1=0,解得m=−4n=1,∴x2+4y2-mxy-n,=x2+4y2+4xy-1,=(x+2y)2-1,=(x+2y+1)(x+2y-1).
∵x2-4x+4与|y-1|互为相反数,∴x2-4x+4+|y-1|=0.∴(x-2)2+|y-1|=0.∴(x-2)2=0,|y-1|=0.∴x=2,y=1.∴(xy−yx)÷(x+y)=(2-12
9.5(100x0,98+2)=9.5x100=950
根号a+4与b的平方-2b+1互为相反数即:a+4=0,b^2-2b+1=(b-1)^2=0a=-4,b=1《x2+4y2》-《axy+b》=x^2+4y^2+4xy-1=(x+2y)^2-1=(x+
依题意得|p+2|+(q2-8q+16)=0,即|p+2|+(q-4)2=0,∴p+2=0,q-4=0,解得p=-2,q=4,∴(x2+y2)-(pxy+q),=(x2+y2)-(-2xy+4),=x
49(x-2y-5)*2