Find the expression that is equilvelent

For this case we have the following expression:
 -18a ^ -2b ^ 5 / -12a ^ -4b ^ -6
 For power properties we have:
 -18a ^ (- 2 - (- 4)) b ^ (5 - (- 6)) / - 12
 Rewriting we have:
 18a ^ (- 2 + 4) b ^ (5 + 6) / 12
 3a ^ (- 2 + 4) b ^ (5 + 6) / 2
 3a ^ 2b11 / 2
 
 3a ^ 2b11 / 2
 option 3

See explanation

Step-by-step explanation:

The average rainfall when you add all 10 years of rainfall up and divide by 10 is an average of 59.946 inches of rain each year. The equation for the data is y = -0.53x + 64.45, this means that the rainfall is getting less each year at a -0.53 inches of rain each year.

x = year (2004 would be 4, etc)