a, \(x\) + (\(x\) + 1) + (\(x\) + 3) = 153
\(x\) + \(x\) + 1 + \(x\) + 3 = 153
3\(x\) + 4 = 153
3\(x\) = 153 - 4
3\(x\) = 149
\(x\) = 149 : 3
\(x\) = \(\dfrac{149}{3}\)
b, (\(2x-7\)) - (\(x\) + 135) =0
2\(x\) - 7 - \(x\) - 135 = 0
\(x\) - 142 = 0
\(x\) = 142