I reccomend that you add an image or better explain what you want us to do.
Using the Polynomial Division: Divide 5
−2
+2x−4 using long polynomial division.
Answer to the Polynomial Division: 
Answer: C.-1.5
Step-by-step explanation:
Given: The burning time of a very large candle is normally distributed with mean
of 2500 hours and standard deviation
of 20 hours.
Let X be a random variable that represent the burning time of a very large candle.
Formula: 
For X = 2470

So, the z-score they corresponds to a lifespan of 2470 hours. =-1.5
Hence, the correct option is C.-1.5.
You can tell if you make the denominators the same easiest one is 30 for 6 and 5
1/5=6/30
1/6=5/30
now you can see which is bigger