The books are $5, and the magazines are $10. I’m not sure which way you want it explained but since magazines are twice the price of books, you can solve the equation 3b + 2b = 25. This gives you b=5 which you just multiply by 2 giving you the price of a magazine.
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.
Interior angles of a triangle should always add up to 180.
180-154=26
26-13=13
X=13
The answer is 16 degrees to your problem.
The second option is true: 3/6= 4/8