PLEASE HELP !!!! ILL GIVE BRAINLIEST !!!

Answer:
Answer below
Step-by-step explanation:
1) The angles are supplementary angles
2) Angle first and is the opposite of the second angle.
3) Let's simplify step-by-step.
3x + (10) (3) x −28
=3x +30x + −28
Combine Like Terms:
=3x +30x + −28
=(3x + 30x) + (−28)
=33x + −28
4) Answer:
=33x −28