`a, 5/8 . 13/19 + 6/19 . 5/8 + 11/16`
`=5/8 .( 13/19 + 6/19) + 11/16`
`=5/8 . 19/19 + 11/16`
`=5/8 .1 +11/16`
`=5/8 + 11/16`
`= 10/16 + 11/16`
`=21/16`
`b, (-3)/7 . 4/13 + (-3)/7 . 9/13 - 5/21`
`=(-3)/7 .( 4/13 + 9/13) - 5/21`
`=(-3)/7 . 13/13 - 5/21`
`=(-3)/7 .1 - 5/21`
`=(-3)/7 - 5/21`
`= (-9)/21 - 5/21`
`=(-14)/21=(-2)/3`
`c,( 5/12 : 11/6 + 5/12 : 11/5) - (-7)/12`
`=(5/12 . 6/11 + 5/12 . 5/11) - (-7)/12`
`=[5/12 .(6/11 + 5/11)] - (-7)/12`
`=[5/12 . 11/11] -(-7)/12`
`= 5/12 - (-7)/12`
`=12/12=1`
#TEAM_IQ_2000
