Plz help me plz I need it and I’m timed

How do you use the additive inverse to evaluate an expression that uses subtraction in a full sentence

What is the slope of the line that contains the points (4,8) and (9,8)? what type of line is it?

Ur environment is very sensitive to the amount of ozone in the upper atmosphere. the level of ozone normally found is 4.04.0 parts/million (ppm). a researcher believes that the current ozone level is not at a normal level. the mean of 2525 samples is 4.44.4 ppm with a standard deviation of 0.80.8. assume the population is normally distributed. a level of significance of 0.020.02 will be used. make the decision to reject or fail to reject the null hypothesis. answer tables