Answer:. . . 18. x = 8β6. . . 19. x = 3. . . 20. x = 3β3. . . 21. x = 5/3Step-by-step explanation:You have already marked the correct relationships on the drawings. Finding the value of x is a matter of making use of those relationships.__18. As you show, x is the given side multiplied by β3, so is ... . . .x = (8β2)(β3) = 8β6__19. As you show, the given side is x multiplied by β2, so .... . . 3β2 = xβ2. . . 3 = x . . . . . . . . . . divide by β2__20. As you show, the given side is x multiplied by β3, so .... . . xβ3 = 9. . . x = 3β3 . . . . . . multiply by (β3)/3__21. As you show, .... . . 8x -10 = 2x. . . 6x -10 = 0 . . . . . subtract 2x. . . x - 10/6 = 0 . . . . divide by 6. . . x = 5/3 . . . . . . . . reduce the fraction and add it to both sdes