Answer:
A = 25
B = 27
C = 5
D = 15
E = 7
Explanation:
The question states that all rows, columns, and diagonals have the same sum. With this assumption, we can add up 6, 16, and 26 to know that each row/column/diagnol adds up to 48. With this in mind, you can fill in the numbers needed to make all the rows add up to 48.
Example: A + 17 + 6 = 48, so A = 25
The more numbers you solve, the more knowledge you have to solve for the rest of the numbers.