Look at the graph of the system of equations:
-x + 2y = -65 x − 3 y = − 3 and 3x + 2y = 2
How can you prove that the point of intersection of the lines on the graph is the solution to both equations?

Substitute 2 as the x value in each of the equations and solve for y.

Substitute 3 as the y value in each of the equations and solve for x.

Substitute -2 as the x value in both of the equations and solve for y.

Substitute -3 as the y value in each of the equations and solve for x.

17. a researcher measures three variables, x, y, and z for each individual in a sample of n = 20. the pearson correlations for this sample are rxy = 0.6, rxz = 0.4, and ryz = 0.7. a. find the partial correlation between x and y, holding z constant. b. find the partial correlation between x and z, holding y constant. (hint: simply switch the labels for the variables y and z to correspond with the labels in the equation.) gravetter, frederick j. statistics for the behavioral sciences (p. 526). cengage learning. kindle edition.

Satchi found a used bookstore that sells pre-owned dvds and cds. dvds cost $9 each, and cds cost $7 each. satchi can spend no more than $45.

How can you tell when x and y are not directly proportional?