2a(y-z)-3b(z-y) 5×3^4+24×3³+63×3² 求因式分解

3（y-z）^2-(2y+z)(-z+2y)这道题我是这样做的：3（y-z）^2-(2y+z)(-z+2y)=3（y-z)^2+(-z-2y)(-z+2y)=3(y-z)^2+z^2-4y^2=3(y^2-2yz+z^2)+z^2-4y^2=3y^2-6yz+3z^2+z^2-4y^2=4z^2-6yz-y^2(a+b-c)^2=[(a+b)-c]^2=(a+b)^2-2(a+b)c+c^2=a^2+b^2-2a+2bc+c^2 解关于x,y,z的方程组5x-y+3z=a,5y-z+3x=b,5z-x+3y=c 2a（y-z）-3b（z-y）用提取公因式法解 将多项式X^2-4Y^2-9Z^2-12YZ分解成因式的积,结果是A.(x+2y-3z)(x-2y-3z)B.(x-2y-3z)(x-2y+3z)C.(x+2y+3z)(x+2y-3z)D.(x+2y+3z)(x-2y-3z) 数学题(x-y)/(y-z),(y-z)/(z-x),(z-x)/(x-y)已知有理数X,Y,Z两两不相等,则(x-y)/(y-z),(y-z)/(z-x),(z-x)/(x-y)中负数的个数是（）A.1个 B.2个 C.3个 D.0个或2个 2a(y-z)-3b(z-y) 5×3^4+24×3³+63×3² 求因式分解 2(x+y-z)-3(x-y+z)-5(x+y-z)+6(x-y+z) 计算 求Y(Z)=Z(Z+2)/(3Z-7)(Z+1)的z反变换 x/2=y/3=z/5 x+3y-z/x-3y+z a+b=3 x+y=3 x+y+z=26 b+c=-2 y+z=5 x-y=1 c+a=7 z+x=6 2x-y+z=18 三元一次方程组,3x+z=7 x-y=3 x-y+z=2x+y+2z=7 x+y=5 y+z-x=-52x+3y-z=12 2x-y+z=18 z-y-x=4对于回答全对者,本人会给予奖励, 2.化简（1）（2x-y+z-2c+m)(m+y-2x-2c-z)(2)(a+3b)(a^2-3ab+9b^2)-(a-3b)(a^2+3ab+9b^2)(3)(x+y)^2(y+z-x)+(x-y)^2(x+y+z)(x+y-z)卷子明天就交,救命.我只有5分, (x+y-z)+(x-y+z)-(x-y-z)和a-2(2a+b)+3(a-b)怎么写 要过程先去括号 再合并同类项 x,y,z 为实数且x+y+z=4√(x-3)+3√(y-6)=6√(z-5),则x+y+z=?x+y+z=4√(x-3)+2√(y-6)+6√(z-5)就可化成：a^2+b^2+c^2+14=4a+2b+6 计算1.(x+y)(x-y)+(y-z)(y+z)+(z-x)(z+x) 2.（a+b-3)(a+b+3) 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/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 已知x,y,z同时满足方程x+3y-5z=0和2x-y-3z=0,则x:y:z的值为（） A.2:已知x,y,z同时满足方程x+3y-5z=0和2x-y-3z=0,则x:y:z的值为（） A.2:1:1 B.3:2:1 C.1:2:1 D.2:3:5 结果试出来了,