The change in altitude after 135 seconds was a decrease of 810 meters, that is, -810 meters.
Given that a weather balloon is descending from the atmosphere, and its altitude changes by -6 meters every second, to determine what is the change in altitude after 135 seconds the following calculation must be performed:
Amount of time x change per second = total change
135 x (-6) = X
-810 = X
Thus, the change in altitude after 135 seconds was a decrease of 810 meters, that is, -810 meters.
