49a. r=9 & r=3
49b. r=59048 & r=19683
49c. The first equation subtracts 1 from 3^n while the second equation subtracts 1 from the value of n.
49d. ***I forgot what an exponential function is, sorry...***
CANT FIGURE OUT 50. Hope I helped...
let's notice, this is a Cube, namely all equal sides, and mind you it has 6 sides, Check the picture below.

Answer:
72.7
Step-by-step explanation:
First multiply 72 by 10
because 72 is 72 10s, making it a whole number.
then add 720 (72 times 10) to 7.
then all of that over 10.
then just divide.
727/10
72.7
this is what you do for all mixed numbers like that one.