令m=2/5 (因为2/5写起来太麻烦了,没有别的意思)
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)
=m
=2/5
(3)规律嘛,只要分子分母乘以相同的系数,分数的值不变
令m=2/5 (因为2/5写起来太麻烦了,没有别的意思)
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)
=m
=2/5
(3)规律嘛,只要分子分母乘以相同的系数,分数的值不变