數學高手！幫幫忙，中學數學題目2個，10點

1st:
(125k^2-20) / (15k-6)
= 5(25k^2-4) / 3(5k-2) = 5(5k+2)(5k-2) / 3(5k-2) = 5(5k+2) / 3

2nd:
= (2p-8) / (4p^2-64) = 2(p-4) / 4(p^2-16) = 2(p-4) / 4(p+4)(p-4) = 1 / 2(p+4)

*** remember that A^2-B^2 = (A+B)(A-B) ***

125k^2 - 20
--------------------- =
15k - 6

(25k + 10)(5k - 2)
--------------------------- =
15k - 6

5(5k + 2)(5k - 2)
------------------------- =
3(5k - 2)

5(5k + 2)
-------------
3



2p -8
-------------- =
4p^2 - 64


(2p - 8)
---------------------- =
(2p - 8)(2p + 8)

1
----------- =
(2p + 8)

1
------------
2(p + 4)