Answer:
y = 11/3
Explanation:
Sometimes it's just how things are written that makes them seem super hard.
R = 6x + 9y is the equation, and then they say what to sub in for x and R. So now we have:
39 = 6(1) + 9y
39 = 6 + 9y
subtract 6 from both sides
33 = 9y
y = 33/9, simplified to 11/3