What is the sum of the fractions? 3/5+-7/5 use the number line to find the answer

The parabola y = x² - 4 opens: a.) up b.) down c.) right d.) left

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?

Thompson and thompson is a steel bolts manufacturing company. their current steel bolts have a mean diameter of 127 millimeters, and a variance of 36. if a random sample of 35 steel bolts is selected, what is the probability that the sample mean would differ from the population mean by greater than 0.5 millimeters? round your answer to four decimal places.