Answer:
; 
Step-by-step explanation:
The inequality says the sum of x and 25 (written as x + 25) is less than (<) 75.
The inequality is written as: 
My work for solving the inequality is in the picture.
Answer:
1117 km
Step-by-step explanation:
Because the two cities are approximately on the same North-South line, they are on the same longitude. The difference in their latitudes is 39° - 29° = 10°. We are subtracting because they are both in the northern hemisphere. The distance between them is

Nothing changes if you don't add anything.
Example:
10+10=20
20+0=20
nothing changes.