tolong di jawab dua duanya mau di kumpul besok

4) (2a)(2x - 6)
---------------------
(3x)(12a)

= (2x - 6)
--------------
3x . 6

= 2x - 6
-------------
18x

= 2(x - 3)
---------------
18x

= x - 3
-----------
9

5) (xy / z) ÷ (x / yz)

= (xy)(yz)
--------------
x . z

= xy²z
-----------
xz

= y²