(1)5/9+x=5/6
x=5/6-5/9
x=15/18-10/18
x=5/18 |
(2)x+1/8=3/4
x=3/4-1/8
x=6/8-1/8
x=5/8
|
(3)x-3/8=5/8
x=5/8+3/8
x=1
|
(4)x-3/7=4/9
x=4/9+3/7
x=27/63+28/63
x=55/63
|
(1) | 1/6、+、5/6 |
(2) | -、1/9、+、2/9 |
(3) | +、- 、+ |
(1)4/7+1/6-3/7
=4/7-3/7+1/6
=1/7+1/6
=13/42
|
(2) 2-7/9-2/9
=2-(7/9+2/9)
=2-1
=1
|
(3)1/4+(2/5+3/4 ) =1/4+3/4 +2/5 =1+2/5 =1又2/5 |
(4)3/5+7/8+2/5 =3/5+2/5+7/8 =1+7/8 =1又7/8 |
(5)7/9-(1/9+1/3) =7/9-1/9-1/3 =2/3-1/3 =1/3 |
(6)5/6-3/10+1/6-3/10 =(5/6+1/6)-(3/10+3/10) =1-3/5 =2/5 |
(1)1-1/5-1/10
=1-2/10-1/10
=7/10
|
(2)1/2-1/5-1/10
=5/10-2/10-1/10
=1/5
|