17.97 + 25.49 + 3x = 50.33
17.97 + 25.49 + 3x - 17.97 - 25.49 = 50.33 - 17.97 - 25.49
3x = 6.87
3x/3 = 6.87/3
x = 2.29 per pair of socks
So since a percent is out of 100 you would put 11/20 and right an equal sign next to that and the bottom fraction would be x/100. Then you would find the relationship between 100 and 20. 20 times 5 is 100 so then 11 times 5 is 55. 55% is your answer