Since the price of Ken’s sandwich was
x dollars, andPaul’s sandwich was 1 dollars more, the price of Paul’s sandwich was x + 1 dollars.Thus, the total cost of the sandwiches was
2x+1 dollars. Since this cost was split evenly, Ken and Paul each paid
=x+0.5 dollars plus a 20% tip. After adding the 20% tip, each of them paid
(x+0.5)+0.2(x+0.5)=1.2(x+0.5)=1.2x+0.6
dollars.
Choices A, B, and D are incorrect. These expressions do not model the given context. They may be the result of errors in setting up the expression or of calculation errors.