Question

How do i add 21p to 35q

Answer 1

I don't think you can because the variables are different. You can only add the same variables.

Answer 2

You can't add 21p + 35q because the variables are different. So 21p + 35q = 21p + 35q. If 35q was 35p we could have added like this:-

21p + 35p 
(27 + 35)p 
62p  

Or if it was 21q instead of 21p we could have added like this:-

21q + 35q
(21 + 35)q
62q

So, you can NOT add 21p to 35q.

Hope I helped ya!! xD