Bagi-bagi poin, please bantuin dong, pake jalan kerjanya juga ya

1) Un = 4ⁿ
    U2 = 4² = 16
    U1 = 4¹ = 4

    r = U2/U1
      = 16/4
      = 4

    Un = a rⁿ⁻¹
     4ⁿ = 4 (4)ⁿ⁻¹
     4ⁿ = 4²⁽ⁿ⁻¹⁾
     n = 2(n - 1)
     n = 2n - 1
     1 = 2n - n
     1 = n
S1 = U1 = 4

2)        (3x - 2)¹/²  -  (2x + 4)¹/²             (3)1/2(3x - 2)⁻¹/² - (2)1/2(2x + 4)⁻¹/²
    lim  ------------------------------- =  lim  ------------------------------------------------
    ₓ→₆             x - 6                      ˣ→₆                           1

                                                 =  3/2 (3(6) - 2)⁻¹/² - (2(6) + 4)⁻¹/²
                                                 =  3/2 (4²)⁻¹/²  -  (4²)⁻¹/²
                                                 =  3/2 (1/4) - (1/4)
                                                 = 3/8 - 2/8
                                                 = 1/8

3)  lim (3x -2) - √(9x² - 2x + 5)  = lim  √(3x -2)² - √(9x² - 2x + 5)
  ˣ→∞                                           ˣ→∞
                                                 = lim   √(9x² -12x + 4) - √(9x² - 2x + 5)
                                                    ˣ→∞
    a = 9
    b = -12
    q = - 2
                                                     b - q
                                                  = -------
                                                      2√a
                                                      -12 -(-2)
                                                  = -------------
                                                         2√9
                                       
                                                        - 10
                                                   = -----------
                                                         2(3)
                                                   = - 10/6
                                                   = - 5/3