A.7/3 B.2 C.10/3 D.3

化简：7(a-b-c)-5(a+b-c)+3(a-b-c)+(a+b-2) (a-b+c/a+b-c)-(a-2b+3c/b-c+a)+(b-2c/c-a-b) 3个不同质数a,b,c,a|(3b-c),b|(a-c),c|(2a-7b),20 已知(3a-b)/3=(a-c)/7=(b-2c)/10,求a:b:c 已知A,B,C满足3a+7b+2c=14,4a+10b+c=16,则a+b-2c= (a-b)(b-c)(c-a)/(b-a)(a-c)2(c-b)3 2a(a+b-c)-3b(a+b-c)+5c(c-a-b) 5a+{3b+[6c-2a-2(a-c)]}-[9a-(7b+c)] 5a-{-3b+[6c-2a-(a-c)]}-[9a-(7b+c）] 5a-｛-3b+[6c-2a-(a-c)}-[9a-(7b+c)] 5a-{-3b+[6c-2a-(a-c)]}-[9a-(7b+c)] 计算：5a-{-3b+[6c-2a-(a-c)]}-[9a-(7b+c)] 初二分式的加减法2a-b-c/（a-b)(a-c)+ 2b-c-a/(b-c)(b-a)+ 2c-b-a/(c-b)(c-a)3a-6b/a+b- 5a-6b/a-b- 4a-5b/a+b+ 7a-8b/b-a注：有空格的地方是下一个分式 2a(b-c)+3(c-b) 化简|a-b|-2c-|c+b|+|3b| c 3a-c=4a+2b-c=a+b+c a:b:c A：B=4:3 B：C=2:7问A:B:C问A:B:C=? 数学a/b=2/3 b/c=4/7 a:b:c求a:b:c=