第1个回答 2015-07-10
1/4+(4/15-1/6)
=1/4-1/6+4/15
=1/12+4/15
=7/20
2/15+(4/5+1/15)
=(2/15+1/15)+4/5
=1/5+4/5
=1
8-5/9+4/9
=8-(5/9-4/9)
=8-1/9
=7又8/9
5/6+9/10+1/6
=(5/6+1/6)+9/10
=1+9/10
=1又9/10
5/9+4/15+4/9+1/15
=(5/9+4/9)+(4/15+1/15)
=1+1/3
=1又1/3
1-5/17-2/17
=1-(5/17+2/17)
=1-7/17
=10/17
5/12-x=1/3
x=5/12-1/3
x=1/12
x-13/20=5/8
x=5/8+13/20
x=19/20本回答被网友采纳
第2个回答 2015-11-18
1/4+(4/15-1/6)
=1/4-1/6+4/15
=1/12+4/15
=7/20
2/15+(4/5+1/15)
=(2/15+1/15)+4/5
=1/5+4/5
=1
8-5/9+4/9
=8-(5/9-4/9)
=8-1/9
=7又8/9
5/6+9/10+1/6
=(5/6+1/6)+9/10
=1+9/10
=1又9/10
5/9+4/15+4/9+1/15
=(5/9+4/9)+(4/15+1/15)
=1+1/3
=1又1/3
1-5/17-2/17
=1-(5/17+2/17)
=1-7/17
=10/17
5/12-x=1/3
x=5/12-1/3
x=1/12
x-13/20=5/8
x=5/8+13/20
x=19/20