what will help you best on problems like these just put a one in front of the letters 4(1b+1n) then it will not be as confusing. Because you have a number to multiply by. you get the same answer either way.
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.
