6/7*4/15+3又3/7除仪3/4-4/5除仪7/8 有简便吗 写出过趁

6/7*4/15+3又3/7除仪3/4-4/5除仪7/8
=(6/7)*(4/15)+(24/7)/(3/4)-(4/5)/(7/8)
=(6/7)*(4/15)+(24/7)*(4/3)-(4/5)*(8/7)
=4/7*3/5+4/7*8-4/7*8/5
=4/7*(3/5+8-8/5)
=4/7*7
=4