Q1: did i do part a right? q2: and how do i do part b?

Part A

0.42 is slightly more than 0.39. You have those two in an incorrect order. So A is the right answer in the wrong order. It's a small error.

Part B

Just multiply the answers you got for A by 10 and subtract.

1 pound oranges =  0.45

10 pounds oranges = 4.50

1 pound bananas = 0.39

10 pounds bananas = 3.90

The difference is the answer.

Difference = 4.50 - 3.90 = 0.60 dollars.

The answer is either 0.60 dollars or 60 cents.

39.9161

Step-by-step explanation:

Correct