-9
9 is positive and 18 is negative, so since 18 is negative, you subtract 18 from 9 and get -9.
To check your answer, on a number line, plot 9, and move 18 to the left.
this makes no sense so maybe try something better
Answer:
9*4*1*2
Step-by-step explanation:
9×4×1×2
Its because you need all the values to find the volume