Which algebraic expression is a polynomial? 3m2n – startfraction 2 m over n endfraction + startfraction 1 over n endfraction startfraction 2 m n over 5 endfraction – startfraction startroot m endroot over 4 endfraction + 4m5 startfraction 4 m cubed over n squared endfraction – 3mn5 + startroot 8 endroot 7mn + startfraction 3 m over 2 endfraction + startfraction 5 n over 4 endfraction

b) 36

step-by-step explanation:

18 times 2 is 36

54 km / hours

step-by-step explanation:

we need to convert seconds to hours

60 seconds = 1 minutes

60 minutes = 1hour

15 m         60 second   60 minutes

  * *         = 54000 meters/ hour

second     1 minute             1 hour

now we need to convert meters to km

1000 m = 1 km

54000 m       1 km

*   = 54 km / hours

hour               1000m