[division of rational expressions][section 54]

(1.)   4a - 16
       _______ ÷ (3a - 12)         here is the problem
          3a

=     4a - 16           1            multiply by the reciprocal
     __________  *  __________
         3a           3a - 12  

=    4(a - 4)         1
     ________  *  ___________
        3a         3(a - 4)             factor

=    4
    ____           cancel and multiply
     9a

(2.)  6z - 27
      _______ ÷ (4z - 18)              here is the problem
         4z

=    3(2z - 9)
    ____________  ÷  2(2z - 9)       factor
        4z

=    3(2z - 9)           1
    ____________ *  __________     multiply by the reciprocal
        4z           2(2z - 9)

=     3
    _____           cancel and multiply
     8z

(3.)   (2x)3          16x2
      _________ ÷  _______          here is the problem
      (4xy)3         8y2z3

=      (2x)3           8y2z3
     __________  *  __________ multiply by the reciprocal
      (4xy)3           16x2   

=    8x3            8y2z3
   _________  *  __________   cube 2 & 4 & multiply exponents
    64x3y3           16x2  

        64x3y2z3

=    _______________     multiply, add exponents
       1024x5y3  


=         z3
     ______________         reduce, subtract exponents
        16x2y


(4.)    a2 - b2           a + b
        ________  ÷   __________
        x2 - y2           x - y         here is the problem

=   (a - b)(a + b)         (x - y)    factor and multiply
   __________________  *  _________  by the reciprocal
     (x - y)(x + y)        (a + b)

=   a - b
    _____
    x + y         cancel and multiply

(5.) x - y       5x2 - 5y2
     _____  ÷   __________             here is the problem
     x + y       3x - 3y

=    (x - y)         5(x2 - y2)
   ___________  ÷   ____________
    (x + y)          3(x - y)        factor

=  (x - y)          5(x - y)(x + y)
   _________  ÷   _________________
    (x + y)            3(x - y)       factor

=    (x - y)             3(x - y)         multiply by the
    ___________  *   _______________    reciprocal
     (x + y)         5(x - y)(x + y)

=    3(x - y)
    ___________
     5(x + y)       cancel and multiply

(6.)   x2 + 2x + 1
      ______________  ÷   (x + 1)   here is the problem
            3x

=   (x + 1)2            1           factor and multiply
   ___________  *  __________  by the reciprocal
        3x          (x + y)

=    (x + 1)
   ___________
       3x                cancel and multiply





(7.)   a3 - 6a2 + 8a        2a - 4
      ______________  ÷  ____________      here is the problem
            5a           10a - 40

=    a(a - 4)(a - 2)        10(a - 4)   factor and multiply
   ___________________  *  ____________  by the reciprocal
           5a               2(a - 2)

=     (a - 4)2       cancel and multiply
   

(8.)      k                       1
      _______________   ÷   ___________
        k2 - 6k + 9            k - 3


=        k                 (k - 3)    factor and multiply
   _________________  *  ____________ by the reciprocal
     (k - 3)2
                1

=   k/(k - 3)             cancel and multiply



(9.)   a2 - 49           3a - 21
     ___________  ÷   _____________    here is the problem
      (a + 7)2           2a + 14

=   (a - 7)(a + 7)           2(a + 7)   factor and multiply
   __________________  *  _____________ by the reciprocal
        (a + 7)2            3(a - 7)

=   2/3            cancel and multiply

(10.)               b2 + 8b + 15
       (b2 - 9) ÷   ______________    here is the problem
                      2b + 10

=   (b - 3)(b + 3)            2(b + 5)      factor and multiply
   _________________  *   ________________ by the reciprocal
           1                (b + 5)(b + 3)

=   2(b - 3)           cancel and multiply