当x=2/5,y=7/20,z=1/4,求x^2yz+xy^2z+xyz^2的值且^是次方 用因式分解

解3元1次方程组：① {2X-Y+Z=-3 {X+3Y-2Z=13 {3X-2Y-Z=2 ② {2X+4Y+3Z=9 {3X-2Y+5Z=11 {5X-6Y+7Z=13 ③ {X+Y+Z+-2 {5X+4Y+Z=O {3X+Y-4Z=11 ④ {X+Y=3 {Y+Z=5 {Z+X=4 ⑤ 当 Y= AX的平方+BX+C 当 X=1时 Y=-4 当 X=3时 Y=-20 当 X=-1时 Y=-12 求A,B 用高斯若尔(G-J)当消元法解下列方程 求过程X+3Y+2Z=-1 2X+Y+2Z=102X+3Y+3Z=-2 4X+4Y+7Z=33-2X+2Y-3Z=7 2X+5Y+12Z=48 {x+y+z=1 {x+3y+7z=2 {x+5y+19z=4 1.{x:y:z=3:4:5 2x+3y-5z=-142.{x-y-z=-1 3x+5y+7z=11 4x-y+2z=-13.{x+y=1 x+z=0 2x+y+2z=44.{x-y+z=-3 2x-y-z=-2 -3x+y+z=-15.{x-y+z=-3 3x+y-4z=6 2x+y-z=36.{x-2y+5z=16 2x+y-5z=7 2x-y+z=38 x-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 分别求出x=?y=?z=? 三元一次方程 X-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 X=?Y=?Z=? {5x-3y+z=2{5x+2y-4z=3{-5x+y-z=2 {x-y-z=-1{3x+5y+7z{4x-y+2x=-1 已知x+y=3,当y+z=4,x+z=5,则x+y+z等于() 当x;y;z=1;3;5时,x+3y-z除以x-3y+z等于多少? 请高手帮我解几道3元1次的方程组!好的100分,x+2y+3z=15x-y+7z=20x+3y+2z=14x+y-z=3y+z-x=5z+x-y=7x+y-z=0.5x-3y+2z=03x+2y-z=23x-2y=12y+3z=2x+5z=315x-3y+2z=13x+4y-z=-18z=136x-y-z=32x-4y+8z=53x-6y-z=10x+y=3y+z=5x+z=6 已知x:y:z=4:5:7,求:(1)2x+3y+z/5z; (2)x+y/y+z. 当4x-3y-6z=0,x=2y-7z=0时,求（x方+2y方+5z方）/(x方+3y方+z方）快 ..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 {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 4X+3Y-2Z=-7,5X-6Y+Z=1,2X+Z=-2 4X+3Y-2Z=-7,5X-6Y+Z=1,2X+Z=-2 帮忙解这几道三元一次方程组(1)X-Y+Z=22X-3Y-Z=-7Z=3(2)X+Y+Z=6X-2Z=12X-2Y+Z=3(3)X+Y=8Y+Z=6Z+X=4(4)X-Y=3Y-Z=4X+Z=5(5)2X+3Y-Z=102X+Y-5Z=8-2X+7Y+Z=20(6)2X+Y+Z=3X+2Y+Z=4X+Y+2Z=5(7)X:Y=2:1X+Y+Z=23X+2Y-2Z=10第一天上课没听懂明天上课绝 (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~