已知(a+2B)/7=(3b-2c)/5=(c-2a)/3,则(3a+b-2c)/(2a-5b+6c)的值为——

已知(a+2B)/7=(3b-2c)/5=(c-2a)/3,则(3a+b-2c)/(2a-5b+6c)的值为——
已知(a+2B)/7=(3b-2c)/5=(c-2a)/3,则(3a+b-2c)/(2a-5b+6c)的值为——

已知(a+2B)/7=(3b-2c)/5=(c-2a)/3,则(3a+b-2c)/(2a-5b+6c)的值为——
(3a+b-2c)/(2a-5b+6c)的值为26/11
令(a+2b)/7=(3b-2c)/5=(c-2a)/3=k
a+2b=7k,(1)
3b-2c=5k (2)
c-2a=3k (3)
(1)*2+(3):4b+c=17k (4)
(2)+(4)*2得：11b=39k,b=39k/11
a=-k/11,c=31k/11
(3a+b-2c)/(2a-5b+6c)
=(-3k/11+39k/11-62k/11)/(-2k/11-195k/11+186k/11)
=26/11