That is not enough information.
If you look at the graphic, diagonal BD (along with point E), can be moved up and down the long diagonal and the two diagonals will still have the same length. You need to state additional information.
Part A.
Before you can write any sort of expression, you need to define variables. "grapes g" is not a definition, so the exercise seems meaningless as written. It seems the intent is to ...
let g, b, p represent the numbers of pounds of grapes, bananas, and pears, respectively.
Then, the total cost of some weight of fruit is
2.19g + 0.59b + 1.49p
Part B.
For g=3, b=3, p=2, the expression evaluates to
2.19*3 +0.59*3 +1.49*2 = 11.32
The total cost of 3 pounds of grapes, 3 pounds of bananas, and 2 pounds of pears is ...
$11.32