若a:2=b:3=c:4=d:5≠0,则a+b+c+d:c=

问题描述:

若a:2=b:3=c:4=d:5≠0,则a+b+c+d:c=

令a:2=b:3=c:4=d:5=x
则a=2x
b=3x
c=4x
d=5x
所以原式=(2x+3x+4x+5x):4x
=14x:4x
=7:2