Step-by-step explanation:
2x + 1 = 16
2x = 15 (subtract 1 on both sides)
x = 7.5 (divide 2 om both sides)
Since 7.5 is not an integer, (a) is No.
However 7.5 is rational, therefore (b) is Yes.
The answer is 86. Hope this helps.
Answer: 729
Step-by-step explanation:

3^-2 = 1/9
3^-4 = 1/81
(-1)^2 = 1
1/(1/9 * 1/81 * 1)
1/ 1/729 = 729
20 + 4 + 3/10 + 5/100 + 7/1000