计算,1.(2b+3a)(3a-2b) 2.(x+y-z)(x-y-z) 3.(3x-2)(2-3x)
计算:1:(2a-3b-c)^2 2:(3y-y-1)(y-3x-1) 3:(2x+y-z)(z-2x+y)
)1.若2的a次方=3,2的b次方=6,求b-a的值.2.运用乘法公式计算(2x+y+z)(2x-y-z)+(y+z)&
1.已知x,y,z∈R,且x+y+z=a 求证x^2+y^2+z^2≥(a^2)/3 2.已知a、b、c>0,a+b+c
已知x,y,z是三个非负数,并且满足3x+2y+z=5,2x+y-3z=1.设k=3x+y-7z,记a为k的最大值,b为
(a-b+c)(-a+b+c)(3a+b-2)(3a-b+2)(x+2y-3z)(x-2y+3z)
、 #define M(x,y,z) x*y+z main() { int a=1,b=2,c=3; printf("%
1.(x+y-z)+(x-y+z)-(x-y-z) 2.2x-(3x-2y+3)-(5y-2)
已知集合A={x|-2≤x<a},B={y|y=2x+3,x∈A},C={z|z=x^2.,x∈A},且C包含于B,求a
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
已知方程组{x+y+z=2,2x-y+z=-1,x+3y+4z=3的解是{x=2-a,y=-2b,z=2-3c,那么a,
计算 1.[(a+b)^2-(a+b)(a-b)]÷(-b) 2.[(x+y)(2x+y)+(x+y)(x-y)]÷3x
定义max{a,b}={a (a>b) ,设实数x,y满足约束条件{|x|≤2,点z={4x+y,3x-y},