(1 2 兀 3)x (1 3 兀 2)y-4-兀=0,那么x-y的值是多少
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3x+2y+z=133x+3y+6z=21得y+5z=812x+2y+4z=142x+3y-z=12得y-5z=-22由1.2得y=3z=1x=2
此题是错的!这是因为cos²(X+Y)+sin²(X+Y)=5121/4225≠1,这与cos²(X+Y)+sin²(X+Y)=1矛盾.
答案为x=2,y=3,z=1;解答过程为:1式与3式相加可得5x+5y=25,算出x+y=5,代入2式得z=1,再把z=1代入可得x=2,y=3;要采纳哦!
(x+5y-13)^2>=0|2x+3y-12|>=0两个非负数互为相反数,则两个数都是0x+5y-13=0(1)2x+3y-12=0(2)2*(1)-(2)得,10y-3y-26+12=07y=14
2x-y/x+3y=2得x+3y/2x-y=1/24x-2y/x+3y减4x+12y除以2x-y=2(2x-y)/x+3y-4(x+3y)/2x-y=2乘以2-4乖以1/2=4-2=2
答案是2.4x-2y/x+3y=(2x-y/x+3y)乘以2=4,4x+12y/2x-y=(x+3y/2x-y)乘以4=1/2x4=2,所以代数式等于4-2=2.
原式=x2+4xy+4y2-2(x2-y2)+2xy-6y2=x2+4xy+4y2-2x2+2y2+2xy-6y2=-x2+6xy,当x=-2,y=12时,原式=-(-2)2+6×(-2)×12=-4
(x+y)-(2x+y/2)-(3x+y/6)-(4x+y/12)-(5x+y/20)-……-(10x+y/90)=x-2x-3x-4x-..-10x+y*(1-1/2-1/6-1/12-..1/90
答案是10所有的多项式都可以消掉到最后只剩下了107x^3-10x^3=-3x^3-6x^3y+6x^3y=0直接消掉+3x^2y-3x^2y=0直接消掉3x^3和第二行剩的那个-3x^3也可以消掉整
(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方=x²-2xy-3y²-x²+4y²-x²+2xy-y²=(x²-
(1){x=y-3{x+y=11y-3+y=112y=14y=7x=y-3=7-3=4所以原方程组的解为x=4,y=7(2){2x+y=13{3x-2y=8y=13-2x3x-2(13-2x)=83x
=(x-y)[(3x+y)-(2x+3y)]*(x-y)=(x-y)*(x-y)(3x+y-2x-3y)=(x-y)(x-y)(x-2y)到底是化简,还是?=(x*x-2xy+y*y)(x-2y)=x
解题思路:根据题意,由整式的运算的知识整理,分析可以求得解题过程:
一、(x-y)^5÷(y-x)^2-(x-y)=(x-y)^5÷(x-y)^2-(x-y)=(x-y)^3-(x-y)=(x-y)[(x-y)^2-1]=(x-y)(x-y+1)(x-y-1)二、(2
解代数式得:-3x的平方y-2y的三次方因为1/2的平方=-1/2的平方,所以结果仍正确给分吧!嘿嘿!
1.x=10,y=9,z=22.x=3,y=2,z=13.x=30,y=20,z=16.
题目想必是漏了平方吧3X²+12XY+13Y²=3(x+3y)(x+y)+4y²=4y²x=-y则有:-y+3y=1y=1/24y²=4*1/4=13
3y=2x,两边同时乘以1/3x可得y/x=2/3;y/3=x/2,两边同时乘以3/x可得y/x=3/2;12/x=9y,两边都乘以x/9可得x/y=4/3.