At a customer service call center for a large company, the number of calls received per hour is normally distributed with a mean of 170 calls and a standard deviation of 20
calls. What is the probability that during a given hour of the day there will be less
than 158 calls, to the nearest thousandth?

Look, when you want to do something like put it like x^2. x2 could mean x² or x₂. so to clear confusion, know the notation. to find the product multiply the x's and you get -8x and the y's and you get 6y. since it's all being multiplied it is just -8x6y, or answer a. although the better answer is -48xy(combining -8 and 6) because you should multiply constants whenever you can.