若a:b:c=4:5:6则2a+3b-c/2a-3b+c=
若a:b:c=4:5:6则2a+3b-c/2a-3b+c=
{A+2B-3C=4,5A-6B+7C=8}求代数式A:B:C 2A-3C/A+2B
a-b=5,b-c=3,(c-a)(2b-a-c)=
若b/a=2,c/b=3,则a+b/b+c=多少
a:b=2:5,b:c=3:4,则a:b:c=
a+2b+3c=5,4a+3b+2c=10,则a+b+c=?,
a+2b+3c=5 3a+2b+c=-4则a+b+c等于?
A/4=B/5=C/6求2A+3B-C/A+B+C
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?
已知a-b/2=b-2c/3=3c-a/4.求5a+6b-7c/4a-3b+9c
a=2,b=3,c=4,则表达式a+b>c&&b= =c&&a||b+c&&b+c的值是多少
若a/b+c=b/c+a=a+c/a+b+2c,则a:b=