What is the slope when the points are (5, -20) and (-10, 40)

How do you solving the solution of each system using elimination?

In the sixth grade 13 out of 20 students have a dog if there are 152 sixth grade students how many of them have a dog

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