Answer:
The total change in the helicopter's altitude is [tex]-58.3[/tex].
Step-by-step explanation:
Create an equation.
[tex]-42.9 +(-15.4)[/tex]
Adding two negative numbers is always negative, so simply add the absolute values and make the answer a negative.
[tex]42.9+15.4 = 58.3[/tex]
Now, change the answer to a negative.
[tex]-58.3[/tex]
Thus, [tex]-58.3[/tex] is the answer.