Explain how you will solve the pair of equations by substitution. show all steps and write the solution in (x, y) form.

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

Susie wants to take her friend out for lunch. she wants to spend $9.75 each person. how much will she spend in all.

Kevin has a spinner that has 10 equal sections and 2 sections of each color—red, blue, green, yellow, and purple. kevin spins the spinner 180 times. kevin determines about how many times the spinner will land on red or green, and his work is shown below. -kevin has the formula reversed; it should be the total number of sections over the number of red or green sections. -kevin should have used a 4 in the numerator because there are 2 red sections and 2 green sections. -kevin should multiply by the number of sections in the spinner rather than the total number of spins. -kevin calculated the prediction correctly and did not make any mistakes.