Which number line represents the subtraction problem 1.5 - 1 = 0.5

When drawing a trend line for a series of data on a scatter plot, which of the following is true? a. there should be an equal number of data points on either side of the trend line. b. all the data points should lie on one side of the trend line. c. the trend line should not intersect any data point on the plot. d. the trend line must connect each data point on the plot.

Jeffery conducted a survey in his school and found that 30 of the 50 eighth grade students' favorite subject is mathematics. based on the results, jeffery concluded that out of the 200 students in his school, 120 students' favorite subject is mathematics. select the statement that is true about jeffery's conclusion. a. jeffery's conclusion is not valid because the sample was biased since only 200 students were surveyed. b. jeffery's conclusion is valid because the sample was random since all of the students were eighth grade students. c. jeffery's conclusion is valid because the sample was random. d. jeffery's conclusion is not valid because the sample was biased since all of the students were eighth grade students.

Write numerical coefficient of y² in the expression 2x² - 15xy – 7y²