3)
Simplify:
3^2 x 3^4

3^6

Step-by-step explanation:

3^2= 9

3^4= 81

81×9 = 729

So

2+4=6

3^6=729

So 3^6

729

Step-by-step explanation:

3^2= 3x3= 9

3^4= 3x3x3x3= 81

81x9=729

Most favorable exchange rate is Friday where the exchange rate is 92.7120 and the worst one is on Wednesday of only 87.5507. 

In the conversion of currency, excluding the surcharge, she will receive only 94% of the exact amount.

Favorable:     ($311.75) x (92.7120/1) x 0.94 = 27,168.788
Least Favorable : ($311.75) x (87.5507) x 0.94 = 25,656.294

The difference between the amounts is 1,512.49 yen.