`a , ( 3567 - 214 ) - 3567`
`= 3567 - 214 - 3567`
`= ( 3567 - 3567 ) - 214`
`= 0 - 214`
`= - 214`
`b, ( - 2007 ) - ( 28 - 2017 )`
`= - 2017 - 28 + 2017`
`= ( - 2017 + 2017 ) - 28`
`= 0 - 28`
`= - 28`
`c, - ( 269 - 357 ) + ( 269 - 357 )`
`= - 269 + 357 + 269 - 357`
`= ( - 269 + 269 ) + ( 357 - 357 )`
`= 0 + 0`
`= 0`