As they are traveling in opposite directions you need to do 50 + 40 to find out how far apart they travel every hour. 50 + 40 = 90. So you know that they are 90 miles apart every hour.
180 / 90 = 2. so you know that it takes them 2 hours to be 180 miles apart.
Answer:
You can use a period or a circle (not colored in)
It go vroom! vroom vroom vroom
30 x 30 = 900
This is the surface area of one side
900 x 6
Multiply by 6 to get the surface area of all 6 sides of the cube
900 x 6 = 5400
