1-8/9*2/7+5/7*3/7 = 一减九分之八乘以七分之二加七分之五乘以七分之三等于多少

1-8/9*2/7+5/7*3/7
=1- 16/63 + 15/49
=1- (7/63 +9/63) +15/49
=1- 1/9 - 1/7 + 15/49
=8/9 + 8/49
=8*(1/9+1/49)
=8* 58/441
=464/441
=1又23/441