计算(a+b+c-d)^2+(a+b-c+d)+(a-b+c+d)^2+(a-b-c-d)^2

[a,b)×[c,d a,b ,c ,d 计算(a+b+c-d)(a-b+c-d) a,b,c,d>0 证(a/(b+2c+3d))+(b/(c+2d+3a))+(c/d+2a+3b))+(d/(a+2b 计算(a+b+c)(c+d+e) 已知a/b=c/d,求证a+2b/b=c+2d/d ( )-(c-d)=(a-c)-(-b+d) (a+b+2c-3d)(a+b-2c+3d)用乘法公式计算. 计算(3a+b-2c+d)(3a-b+2c+d) 求行列式 |a+b+c+2d a b c,d b+c+d+2a b c,d a a+c+d+2b c,d a b a+b A B C D × 9 ___________________ D C B A (1) A = ( )(2) B = ( a+b+c+d=2a;a+b+c+d=4b;a+b+c+d=6c;a+b+c+d=8d 求a,b,c,d