(a).
Simplify the expression to obtain the value at missing place.

Blank space: 35
(B).
Simplify the expression to obtain the value of missing place.

Blank space : 7
(C)
Simplify the expression to obtain the value at missing place.

Blank space: 2
16 2/12
I hope this helps :)
Sum means to add, so you are adding a and 46 to get k. k is given as 97 so your equation used to solve for a is a + 46 = 97, choice A from above.