The sequence:
-18 , -22.5 , -27 , -31.5 , -36
Common difference:
(-18 - -22.5) = (-22.5 - -27) = (-27 - -31.5) = (-31.5 - -36) = 4.5 ( When two minuses come together, they make a plus. So difference is certainly the positive next number - positive previous number to give 4.5)
Common difference = 4.5
Type of the sequence: Arithmetic sequence.
