What is the coefficient of y in the expression 2 ⋅ 3 + 9y? Which expression represents "7 times the sum of 4 and y?"

Four expressions are shown:

10x + 6

12x + 4

2(5x + 3)

2(6x + 2)

Which two expressions are equivalent to 2(5x + 2 + x)?

 Which expression is equivalent to 2a + 2a?​

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.