计算：1.(-x+2y+3z)(x-2y-3z) 2.[(x/2+3y)^2-(y/2+x)^2+(3x-2/y)^2-

来源：学生作业帮编辑：神马作文网作业帮分类：数学作业时间：2024/11/15 14:20:43

计算：1.(-x+2y+3z)(x-2y-3z) 2.[(x/2+3y)^2-(y/2+x)^2+(3x-2/y)^2-(x/2+3y)(3y-y/2)]÷x/2

1.原式=[x+(2y+3z)][x-(2y+3z)]
=x²-(2y+3z)²
=x²-4y²-12yz-9z²
2 .原式=(x²/4+3xy+9y²-y²/4-xy-x²+9x²-3xy+y²/4-9y²+x²/4)÷(x/2)
=(17x²/2-xy)÷(x/2)
=17x²/2÷(x/2)-xy÷(x/2)
=17x-2y
再问：第一题，是（﹣x+2y+3z)(x-2y-3z)
再答： 1.原式=[-x+(2y+3z)][x-(2y+3z)] =-x²-(2y+3z)² =x-²-4y²-12yz-9z²

1.（x+y-z)+(x-y+z)-(x-y-z) 2.2x-(3x-2y+3)-(5y-2) 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 计算：3x-2y- [-4x+(z+3y)] 计算：1.(-x+2y+3z)(x-2y-3z) 2.[(x/2+3y)^2-(y/2+x)^2+(3x-2/y)^2- x/2=y/3=z/5 x+3y-z/x-3y+z (y-x)/(x+z-2y)(x+y-2z)+(z-y)(x-y)/(x+y-2z)(y+z-2x)+(x-z)(y-z 因式分解：25x y^2 z^2 (x+y-z)-30xyz(z-x-y)^2+5x y z^3 (z-x-y) 已知x,y,z 大于0,x+y+z=2,求证 xz/y(y+z)+zy/x(x+y)+yx/z(z+x)大于等于2/3 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, 计算（x+2y-3z)的平方+（x-2y+3z)(x+2y-3z) (x+2y+3z)-(3x+2y-z)+(2x-3y+4z) 用直式计算 (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai