What is n in the equation 9n + 2/3 n = 4

So that they have the same denominator you can rewrite 9n as (27/3) n

(27/3) n + (2/3) n = 4

(29/3) n = 4

Multiply both sides by 3/29 to isolate variable n.

n = 4 (3/29)

n = 12/29