1/2a+1/2b+1/2c>或=1/(b+c)+1/(a+b)+1/(a+c)
1/2a+1/2b+1/2c>或=1/(b+c)+1/(a+b)+1/(a+c)
1.计算:(1)(a-b)(a-c)分之2a-b-c + (b-c)(b-a)分之2b-c-a + (c-b)(c-a)
A=B+B+B+B+B+B+B+B+B+B+B+B+B+B+B A-B×3=C C+2×7+2=1
..a b c为正,求证a^2/(b+c)+b^2/(c+a)+c^2/(a+b)>=1/2(a+b+c)
1、化简:| b-c |+| a-b |-| a+c | 2、化简:2c+|a+b|+
已知a,b,c是正实数,满足a^2=b(b+c),b^2=c(c+a).证明:1/a+1/b=1/c
设a+b+c,b+c-a,c+a-b,a+b-c成G.P,公比为a/c,试证r^3+r^2+r=1
b/(a+c)=1/2,a/(b+c)=1/5 怎么得出a/(a+b+c)=1/6,b/(a+b+c)=1/3?
a=2,b=-3,c=-1,计算:|a-b|+|b-c-a|.
A B C D × 9 ___________________ D C B A (1) A = ( )(2) B = (
(a,b)=1 (a,b)|c
计算或化简(x-1)(x-2)-(2-x)^2(a+b-c)(c+a+b)-(a+b)^