已知二分之a等于五分之b等于七分之c,且a+b+c不等于零,则a+b+c分之2a+3b-2c的值为多少
问题描述:
已知二分之a等于五分之b等于七分之c,且a+b+c不等于零,则a+b+c分之2a+3b-2c的值为多少
答
设a/2=b/5=c/7=t,
∴a=2t,
b=5t,
c=7t,
(2a+3b-2c)/(a+b+c)
=(4t+15t-14t)/(2t+5t+7t)
=5t/14t
=5/14.