2a+b-c≠0
(a+b)/3=(2c-b)/4=(2a+c)/5=k
k≠0,
a+b=3k,2c-b=4k,2a+c=5k
a+c=4k,a=k,c=3k,b=2k
(3a+2b+c)/(2a+b-c)
=(3k+4k+3k)/(2k+2k-3k)
=10
2a+b-c≠0
(a+b)/3=(2c-b)/4=(2a+c)/5=k
k≠0,
a+b=3k,2c-b=4k,2a+c=5k
a+c=4k,a=k,c=3k,b=2k
(3a+2b+c)/(2a+b-c)
=(3k+4k+3k)/(2k+2k-3k)
=10