`a) 70 - ( x - 3) = 45`
`=> x - 3 = 70 - 45 = 25`
`=> x = 25 + 3 = 28`
`b) 12+ ( 5 + x) = 20`
`=> 5 + x = 20 - 12 = 8`
`=> x = 8 - 5 = 3`
`c) 130 - ( 100 + x) = 25`
`=> 100 + x = 130 - 25 = 105`
`=> x = 105 - 100 = 5`
`d) 175 + ( 30 - x) = 200`
`=> 30 - x = 200 - 175 = 25`
`=> x = 30 - 25 = 5`
`e) ( x + 12) + 22 = 92`
`=> x + 12 = 92 -22 = 70`
`=> x = 70 - 12 = 58`
`f) 95 - ( x + 2) = 45`
`=> x + 2 = 95 - 45 = 50`
`=> x = 50 - 2 = 48`
