Answer:
Step-by-step explanation:
Since he is going to use 3/4 of a gallon of each you are just subtracting 3/4 from each value. so
1 1/8 - 3/4
1 1/9 - 3/4
7/8 - 3/4
For me, I always turn mixed numbers into improper fractions. Pleae let me know if you don't know how to do this.
9/8 - 3/4
10/9 - 3/4
7/8 - 3/4
Now, to subtract fractions you want them to have the same denominator. For example, 3/5 - 1/2 you have t change both to be 6/10 - 5/10 = 1/10. So, how do we do that for each?
9/8 and 3/4 is easy, we can make 3/4 = 6/8 so then it's 9/8-6/8 = 3/8
10/9 - 3/4 is kinda unpleasant. We have to change both. The easiest thing to do is multiply the numerator and denominator of one by the denominator of the other. That might be confusing so I'l write it out.
(10*4)/(9*4) - (3*9)/(4*9) = 40/36 - 27/36 then just subtract like you did for the last one. Also keep in mind you have to look out if you can simplify.
The last one is just like the first. Can you manage it yourself? If not I can walk you through it a bit?