To write 7.32 as a fraction you have to write 7.32 as numerator and put 1 as the denominator. Now you multiply numerator and denominator by 10 as long as you get in numerator the whole number.
7.32 = 7.32/1 = 73.2/10 = 732/100
And finally we have:
7.32 as a fraction equals 732/100


The domain would be -2, the x-intercept.
I believe that the question is assuming this is taking place over one month here is what I think you would do.
1) 75/12.5 = 6
2) add that answer to 75, so 75+6, and you get 81