一:若a/b=c/d=e/f=2/5,求(1)(a-c)/(b-d);(2)(2a+3c-4e)/(2b+3d-4f)(3)比較的結論,發現什麼規律

一:若a/b=c/d=e/f=2/5,求(1)(a-c)/(b-d);(2)(2a+3c-4e)/(2b+3d-4f)(3)比較的結論,發現什麼規律

令m=2/5(因為2/5寫起來太麻煩了,沒有別的意思)a/b=m所以a=bm同理可得,c=dm,e=fm(1)(a-c)/(b-d)=(bm-dm)/(b-d)=m(b-d)/(b-d)=m=2/5(2)(2a+3c-4e)/(2b+3d-4f)=(2bm+3dm-4fm)/(2b+3d-4f)=m(2b+3d-4f)/(2b+3d-4f)=…