Answer:
Haven't done this in a while but here goes: Top left FF - Top right Ff - Bottom left fF ( or Ff?)- bottom right ff.
Step-by-step explanation:
Freckles are dominant trait so Capitalized letter F ( i chose "F" because the question told me to choose a random letter to use in this problem). Yet, one son doesn't have them so there must be a presence of a recessive allele (hence, little f). This all means that both parents have one dominant allele and one recessive allele. Each one has "Ff". So then you fill it in. The first gamette of each is "F" so when the box asks for Gamette 1 you put an F and when it asks for a gamette 2 you put in a "f". Now the bottom right might be "Ff" just because you would follow the traditional order of putting the dominant allele first but, I wasn't sure. Hence the "Ff/fF" I put. That itslef wouldn't be the final answer but two options of what I believe it would be. You might know which to choose as you've seen it in class but yeah.
Here again, I haven't done this in a REALLY long time so take this with a literal grain of salt and if it doesn't line up with what you've learned in class, please disregard this response!
Let me know what it ends up being!