19 and 20 plz and show how it’s done

19. 12 feet below the surface

Assume the surface to be zero on a vertical number line. Then the diver is positioned at - 26. He then rises + 14. Finally his position is

-26 + 14 = - 12

That is he is 12 feet below the surface.

20. x = - 2

multiply both sides by 2 to eliminate the fraction.

- 24 = 6x - 12

add 12 to both sides

- 24 + 12 = 6x

- 12 = 6x

divide both sides by 6

- = x ⇒ x = - 2

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