两道简算题,急用!(1/4+5/8)/(7/4-7/8)(3/5-1/4)/(3/4+1/5)_数学解答

两道简算题,急用!
(1/4+5/8)/(7/4-7/8)
(3/5-1/4)/(3/4+1/5)

人气：169 ℃　时间：2020-05-27 09:57:26

解答

1.(1/4+5/8)/(7/4-7/8)
=7/8 / 7/4 - 7/8 / 7/8
=7/8 * 4/7 - 7/8 * 8/7
=1/2 - 1
=-0.5
2.简算我也不会,答案是7/19.