Help pleaseeee I'll mark brainliest!!

Answer:
D. 1/2 +1/2·1/3
Step-by-step explanation:
To find an appropriate expression, we can work through the amounts eaten day by day:
Marcus ate 1/2 of the pizza, so 1 -1/2 = 1/2 of the pizza was left.
Marcus ate 1/3 of what was left, so ate (1/2)(1/3) of the pizza.
The amount Marcus ate in total is the sum of the amounts eaten on Monday and Tuesday:
1/2 + (1/2)(1/3) . . . . . matches choice D