you have to look at the y as 7 plug the 7 in the parentheses on the left side of the minus sign and you get 63. Now look at the 4x. X is now replaced with 4. 4 times 4 is 16. 63 minus 16 is 47.
Add 11 + 16. Plug in 11 into b-2 since b equals eleven. You should now have 11+16+11-2. Do the same thing and plug in 16 for c and 11 for b for c-b. Your solution will now be 11+16+11-2+16-11.