Answer:
k = 500 - a
Step-by-step explanation:
[tex]k + a = 500[/tex]
As we need "k" alone in one side of eqn. , we need to substract "a" on both the sides of the eqn. so that we can cancel "a" which on the left side.
[tex]k + a - a = 500 - a[/tex]
[tex] = > k = 500 - a[/tex]
