18:(x-1)=2:718*7=2*(x-1)9*7=x-163=x-1x=64
根据比例的性质.内项的积等于外项的积2(x-1)=18*7(x-1)=63x=64小朋友,加油啊!
18:(x-1)=2:7 18*7=2*(x-1) 9*7=x-1 63=x-1 x=64笨
64
