For the first one, to find x, you are going to take that entire side which would equal to 180 and solve. 2x+20+55=180 would then go down to 2x+65=180 once you add the 20 and 55. Then subtract 65 to both sides and divide your final answer 115/2 which is x=57.5. For the second one it’s 4x-2+21=180, then you will subtract 2 from 21 and get 19. After you would subtract 19 by 180 and divide 4 by each side, getting x=40.25 as your final answer.