2(5 + X) - 1 = 3X + 9
Step 1: Expand the terms in the bracket
=> 2 x 5 + 2 x X - 1 = 3X + 9
=> 10 + 2X - 1 = 3X + 9
Step 2: collect like terms
=> 2X - 3X = -10 + 1 + 9
=> -X = 0
