Explanation:
✲

Remove the unnecessary brackets :
⇢

Combine like terms. Like terms are those which have the same base. Only coefficients of like terms can be added or subtracted.
⇢

⇢


Hope I helped ! ♡
Have a wonderful day / night ! ツ
▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁