Answer:

Step-by-step explanation:
If I represent the worker's position relative to the surface of the earth then
if we let Δy = the change of position.

You can solve this by algebraically as well as graphically. When I tried both ways I got:
solution is x= -2<span />
The sequence:
a 1 = 30, a 2 = 70, a 3 = 110, a 4 = 150, a 5 = 190,...
a 2 = a 1 + d
70 = 30 + d
d = 70 - 30 = 40
a n = a 1 + ( n - 1 ) * d
For the 25th month:
a 25 = 30 + 24 * 40 = 30 + 960 = 990
Answer: B ) 990.