y=8 2x-1 1

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y=8 2x-1 1
3x+2=y 5X+4=Y 7X+6=Y 9X+8=y 11x=y要如何计算

3x+2=y和11x=y,得到x=1/4,y=11/4,5X+4=Y和7X+6=Y,得到X=-1,Y=-1代入9X+8=y,不成立,方程组无解..

3x-2y=15 3y-2x=11 求x+y

3x-2y=153y-2x=11两式相加可得x+y=26

已知x+y/x=11/8,求x-y/x+2y的值

(x+y)/x=11/88x+8y=11y8x=3yy=8x/3(x-y)/(x+2y)=(x-8x/3)/(x+16x/3)=(-5x/3)/(19x/3)=-5/19

3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27

化简得:-x+7y=11①7x+3y=27②①式×7得:-7x+49y=77③②+③得:52y=104∴y=2代入①得:x=3∴x=3,y=2再问:亲,是代入法哦!再答:代入法①式得3x+3y-4x+

3x+2=y 5x+4=y 7x+6=y 9x+8=y 11x=y

将11x=y即y=11x分别代入前面四个方程式,1、方程式一得3x+2=11x,x=1/4,则y=11/4;2、方程式二得5x+4=11x,x=2/3,则y=22/3;3、方程式二得7x+6=11x,

7x+3y=44,11x+2y=61,求x,y

联立两个方程7x+3y=44(1)11x+2y=61(2)将方程(1)左右两边同时乘以2,方程(2)左右两边同时乘以3原方程组化为14x+6y=88(3)33x+6y=183(4)用方程(4)-(3)

(3x+2y)(4x-5y)-11(x+y)(x-y)+5xy,其中x=2分之七,y=-2分之5

(3x+2y)(4x-5y)-11(x+y)(x-y)+5xy=12x²-7xy-10y²-11x²+11y²+5xy=x²-2xy+y²=

(11x+y)(-11x+y)+(11x+y)的平方=?

(11x+y)(-11x+y)+(11x+y)的平方=y^2-(11x)^2+(11x)^2+y^2+2*11xy=2y^2+22xy(x-2y)(x+2y)-(x+2y)的平方-(x-2y)(2y-

{x=y-3 {x+y=11 {2x+y=13 {3x-2y=8

(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

解方程组 {3(x+y)-4(x-y)=11 {2(x-y)+5(x+y)=27全过程、快

方程化为-x+7y=1117x+3y=272将1式化为x=7y-113则将3式代入2式可得7(7y-11)+3y=2752y=104y=2x=7×2-11x=3所以解得x=3y=2

{x+y=5{3x-7y=11

①x+y=5②3x-7y=11将①×7得:③7x+7y=35用②+③得:④3x-7y+7x+7y=11+35,即10x=46,即x=4.6代入①得:y=5-x=0.4

y-3x=2,y-5x=4,y-7x=6,y-9x=8,y-11x=0方程组,

最后一个应该是:y-11x=10吧这样解就是X=-1,Y=-1否则无解

(3x-2y)(4x-5y)-11(x+y)(x-y)+5xy,已知X=3又1/2,y=2又1/3

(3x-2y)(4x-5y)-11(x+y)(x-y)+5xy=12x^2-23xy+10y^2-11x^2+11y^2+5xy=x^2-18xy+21y^2=x^2-10xy+21y^2-8xy=(

已知x+y/y=11/8,求x-y/x+2y的值.

x+y/y=11/8说明11y=8(x+y)即8x=3y所以x-y/x+2y=3(x-y)/3(x+2y)=(3x-3y)/(3x+6y)=(3x-8x)/(3x+16x)=-5/19

不解方程组2x-y=12 x+2y=11求(2x-y)^3-(2x-y)^2(x-3y)的值

(2x-y)^3-(2x-y)^2(x-3y)=(2x-y)^2*(2x-y-x+3y)=(2x-y)^2*(x+2y)=12^2*11=1584

解方程组x+y/3=x-y/4 2x+3y=11

x+y/3=x-y/4⑴2x+3y=11⑵由⑴得x+7y=0,x=-7y(3)将(3)代入⑵得y=-1所以x=7

已知方程组2x-y=10,x+2y=11,求(2x-y)³-(2x-y)²(x-3y)的值

(2x-y)³-(2x-y)²(x-3y)=(2x-y)²[(2x-y)-(x-3y)]=(2x-y)²(x+2y)=10²×11=1100

解方程组 {3(x+y)-4(x-y)=11 {2(x-y)+5(x+y)=27

化简得:-x+7y=11①7x+3y=27②①式×7得:-7x+49y=77③②+③得:52y=104∴y=2代入①得:x=3∴x=3,y=2

3x+2=y 5x+4=y 7x+6=y 9x+8=y 11x=y 联立方程 有的话

3x+2=y5x+4=y7x+6=y9x+8=y有解x=-1,y=-111x=y按前面的规律,是不是少加了一个10?应该是11x+10=y?是的话,解就是x=-1,y=-1了

已知x=2,y=3,求代数式(x-y)*(x-y)^3*(x-y)^5*……*(x-y)^11

x-y=2-3=-1所以(x-y)*(x-y)^3*(x-y)^5*……*(x-y)^11=(-1)*(-1)²*(-1)²*.(-1)^11=-1*1*(-1)...(-1)=(