Final answer:
There are 171 Gala apple trees and 174 Red Delicious apple trees in the orchard.
Step-by-step explanation:
Let's denote the number of Gala apple trees as 'x'. Since there are 2 more Red Delicious trees than Gala, then the number of Red Delicious trees is 'x + 2'.
According to the given information, the total number of trees is 345. So, we can form the equation: x + (x + 2) = 345.
By solving this equation, we find that there are 171 Gala apple trees and 174 Red Delicious apple trees in the orchard.