计算题要简算

[3/5+1/5]+[2/3-12/17]-[1/5+5/17]
=3/5+1/5+2/3-12/17-1/5-5/17
=（3/5+1/5-1/5)+2/3-(12/17+5/17)
=3/5+2/3-1
=9/15+10/15-1
=4/15
其实它本来自己就很简单了的( ⊙ o ⊙ )啊！··把分母分别为17和5的合并

开括号，就简单多了