a)2/3+(5/7+-2/3) b)1/15+1/35+1/63+1/99+1/143 c)1/5.4/7+3/7.1/5-1/5 d)-1/9.-3/5+5/-6.-3/5-7/2.3/5 e)5/-13+-5/7+-20/41+8/13+-21/41 g)6/7.8/13+6/7.9/13-3/13.6/7 h)-3/7.15/13-3/7.11/13-3/7

`a)` `2/3` `+` `( 5/7 + - 2/3 )`

`=` `2/3` `+` `1/21`

`=` `5/7`

`b)` `1/15` `+` `1/35` `+` `1/63` `+` `1/99` `+` `1/143` 

`=` `2/21` `+` `2/77` `+` `1/143`

`=` `4/33` `+` `1/143`

`=` `5/39`

`c)` `1/5` `×` `4/7` `+` `3/7` `×` `1/5` `-` `1/5`

`=` `1/5` `×` `( 4/7 + 3/7 )`

`=` `1/5` `×` `1`

`=` `1/5` 

`d)` `- 1/9` `×` `- 3/5` `+` `5/- 6` `×` `- 3/5` `-` `7/2` `×` `3/5`

`=` `3/5` `×` `( - 1/9 + 5/- 6 - 7/2 )`

`=` `3/5` `×` `- 40/9`

`=` `- 8/3`

`e)` `5/- 13` `+` `- 5/7` `+` `- 20/41` `+` `8/13` `+` `- 20/41`

`=` `- 100/91` `+` `68/533` `+` `8/13`

`=` `- 3624/3731` `+` `8/13`

`=` `- 1328/3731`

`g)` `6/7` `×` `8/13` `+` `6/7` `×` `9/13` `-` `3/13` `×` `6/7`

`=` `6/7` `×` `( 8/13 + 9/13 - 6/7 )`

`=` `6/7` `×` `41/91`

`=` `246/637`

`h)` `- 3/7` `×` `15/13` `-` `3/7` `×` `11/13` `-` `3/7`

`=` `- 3/7` `×` `( 15/13 - 11/13 - 3/7 )`

`=` `- 3/7` `×` `- 11/91`

`=` `33/637`

$#Shawnnn$