Question

Two numbers have a sum of 50 If one number is​ p, express the other number in terms of p.

Answer 1

the other number is 50 - p

Consider a numeric example

2 numbers sum to 5 , one of the numbers is 3 what is the other ?

Obviously 2 , that is 5 - 3 = 2 gives the number

In the same way the number here is p and 50 - p is the other number