Answer:
319 feet
Step-by-step explanation:
Let x be the initial height of the jet liner.
Take a "drop" as a negative value and a "climb" as a positive value.
If the jet liner drops 259 feet:
⇒ x - 259
If it then climbs 123 feet:
⇒ x - 259 + 123
If it then drops another 183 feet:
⇒ x - 259 + 123 - 183
Simplify:
⇒ x - 259 + 123 - 183
⇒ x - 136 - 183
⇒ x - 319
Therefore, the overall vertical change is 319 feet.
