8a + 3 - a - 2 = 1 - 7a
[Collect the like terms and the subtract the numbers]
=> 7a + 1 = 1 - 7a
[Cancel equal terms on both sides of the equation]
=> 7a = - 7a
[Move variables to the left side and change its sign]
=> 7a + 7a = 0
[Collect the like terms by adding their coefficients]
=> 14a = 0
[Divide both sides of the equation by 14]
=> a = 0