16. Direct Variation or y_2 = ? and Inverse Variation or y_2 = ?
17. Direct Variation or x_2 = ? and Inverse Variation or x_2 =?
18. Direct Variation or x_1 = ? and Inverse Variation or x_1 = ? *
19. Direct Variation or y_2 = ? and Inverse Variation or y_2 = ? *
20. Direct Variation or y_2 = ? and Inverse Variation or y_2 = ? *
