Answer:

Step-by-step explanation:

Multiply by 10 on both sides,

so 
The volume of the triangular prism = 
Thus the volume is
.
Thus the volume is 42 cubic km.
Hope that helps!
Answer:
Question 2 is the right answer.
Step-by-step explanation:
Answer:
As number of gallons of gas minus 9 leaves 3 gallons, denote g as number of gallons: g - 9 >=3.
Then g>= 12