`a)19/24-49/25+5/24-51/25`
`=(19/24+5/24)+(-49/25-51/25)`
`=1+(-4)`
`=-3`
`b) 46 ( 51 - 47 ) - 51 ( 46 - 27 ) `
`= 46.51 - 46.47 - 51.46 + 51.27 `
`= 51.27 - 46.47 `
`= -785 `
`c) -5/-15 + 9/7 + 1/-3 - 276/14 `
`= 1/3 + 1/-3 + 9/7 - 138/7`
`= -129/7`
`d) 5.6 + 6.3 / 18.5`
`= 6(5+3)/18.5`
`= 6.8/18.5`
`= 8/3.5`
`= 8/15`