He uses 2/3 of a gallon each hour he works.
Answer:
or
is used
Step-by-step explanation:
Daniel uses the proportions of
cups of orange juice and
cups of carrot juice to make a mixed juice.
Now, in the question 1 cup of carrot juice is used. So 4 times of the proportion of the carrot juice is used. Accordingly 4 times of the cups of orange juice will be used.

So for one cup of carrot juice
or
is used.
The length of all the sides is same, if u want to write it as an expression, you can write it as any variable, x,y or z