Question

the distance from the earth to the sun equals 1 au. neptune is 30 au from the sun. how far is neptune from the earth? \boxed{} au

Explanation:

Step1: Identify two distance scenarios

Earth-Sun: $1$ AU, Neptune-Sun: $30$ AU

Step2: Calculate closest distance

Subtract Earth-Sun from Neptune-Sun: $30 - 1 = 29$ AU

Step3: Calculate farthest distance

Add Earth-Sun to Neptune-Sun: $30 + 1 = 31$ AU

Answer:

29 AU (closest alignment) or 31 AU (farthest alignment)