it can be written as the equation
(x) + (3x) + (x + 3) = 23
since addition has communicative property, then you can get rid if the parenthesis. so the equation becomes:
x + 3x + x + 3 = 23
then you can add like terms (x) to get
5x + 3 = 23
then you can subtract 3 from both sides to get 5x = 20
the you isolate x by dividing both sides by 5 to get:
x = 4
that is the answer to this equation