The way the table works is that you take the sum of the number on the top row with the number on the side to find the value of the entry at their crosshairs.

In that way, we learn that 4 + y = -5, and thus y = -9.

We also learn y + e = n. Plugging in, we have -9 + e = n.

Similarly, we have z + 4 = m and z + e = 10. Subtracting the first equation from the second, we get:

e - 4 = 10 - m, so
e = 14 - m

Plugging this into -9 + e = n, we get
- 9 + 14 - m = n

Thus, 5 = m + n and our answer is C.

Tatiana

thanks much...


Sukrant

Is this a standard table definition? I wasn't familiar with its definition.