3x+2y+z=13 (1) x+y+2z=7 (2) 2x+3y-z=12 (3)

方程组 (1) x+2y-3z=12 x-3y+2z= - 13 x-y-z=0 (2) x+ y=z 5x-y+z=18 2x+5y+3z= -1 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 分式加减的几道题目求速度1 .(x+y)²/（x-z)(y-z) - (y+z)²/（x-z)(y-z) = 2.2x+3y/x-y+2y/y-x-3y/x-y= x+y+z=6 x+2y+3z=14 y+1=z 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 若|x+3|+|y-2|+|2×z+1|=0求(x×z-y×z)(y-x+z)的值 三元一次方程(需过程!)(1)x+y=-2y+z=1z+x=13(2)3x+2y+z=4x+y+z=103x+3y-z=1(3)2x+y+z=2x+2y+z=4x+y+2z=6(4)6x-3y+z=83x+y+4z=3x-2y+3z=-3 ..1.x+y+z=26,2.4y+3z=7,y-z=1,3x+2z=17,x+2y-z=18 9x-7y=173.x-7y+3z=17 4.2x+4y+3z=95x-6y-z=24 3x-2y+5z=113x+7y-2z=1 5x-6y+7z=131.x+y+z=26,y-z=1x+2y-z=18 2.4y+3z=7,3x+2z=11,9x-7y=17 3.x-7y+3z=17 5x-6y-z=24 3x+7y-2z=14.2x+4y+3z=93x-2y+5z=11 5x-6y+7z=13 (1)2X+4Y+3Z=93X-2Y+5Z=115X-6Y+7Z=13(2)X:Y=3:2Y:Z=5:4X+Y+Z=66(3)3X-Y+Z=32X+Y-3Z=11X+Y+Z=13以上3个题目为三元一次方程~ matlab解对数方程组[x,y,z]=solve('0.29744*x/(3+0.1*x+y+z)=(log10((3+x+y+z)/(3+0.1*x+y+z)))^2','0.79*x/(3+0.1*y+z)=(log10((3+x+y+z)/(3+0.1*x+y+z)*(3+y+z)/(3+0.1*y+z)))^2','1.25*x/(3+0.1*z)=(log10((3+x+y+z)/(3+0.1*x+y+z)*(3+y+z)/(3+0.*1y+z)*(3+z)/ 1、y-x/x²-y²2、(x-y)(y-z)(z-x)/(z-y)(y-x)(x-z) x+2y-z=0 2x-3z=1 3x-y+2z=4x+2y-z=02x-3z=13x-y+2z=4 证明 ：x/(y+z)+y/(z+x)+z/(x+y)>=3/2其中 x,y,z>0 1.5x-3y+z=25x+2y-4z=3-5y+y-z=2以上是第一题.2.x+y=-2x+z=13y+z=1以上是第二题.3.x-y-z=-13x+5y+7z=114x-y+2z=-1以上是第三题. 求X Y Z各代表什么数,使下列等式成立1、X+X+X=Y+Y；2、Y+Y+Y+Y=Z+Z+Z；3、X+Z+Y+Y=180 求方程组 ｛x+y-z=1 2x+3y-z=13