What am I doing wrong?

[debbie29]

What am I doing wrong... or even worse, am I doing anything right at all?

Question: (all one question-- two dividing signs for you all to make it easier to read)
3a^2 + 12 / A^4-16
3a^2- 15a / a^2- 3a- 10



My work:



Flip right side, change to multiplication.



3(a^2+4)(A-2a)(A-5)
3a(A-5)(A^2+4)(A^2-4)



= 3(a+2a)
3a(a^2-4)

= 3 (A+2a)
3a (a+2) (A-2)

 

[Denis]

What am I doing wrong... or even worse, am I doing anything right at all?

Question: (all one question-- two dividing signs for you all to make it easier to read)
3a^2 + 12 / A^4-16
3a^2- 15a / a^2- 3a- 10



My work:



Flip right side, change to multiplication.



3(a^2+4)(A-2a)(A-5)
3a(A-5)(A^2+4)(A^2-4)



= 3(a+2a)
3a(a^2-4)

= 3 (A+2a)
3a (a+2) (A-2)

Boy oh boy...WHY have you got capital A's here and there?

Start by flipping ONLY (less confusing):
(3a^2 + 12)(a^2 - 3a - 10)
-------------------------------
(3a^2 - 15a)(a^4 - 16)

Now do initial factoring:
3(a^2 + 4)(a - 5)(a + 2)
-------------------------------
3a(a - 5)(a^2 + 4)(a^2 - 4)

Cancel like terms:
a + 2
--------------
a(a^2 - 4)

Factor a^2 - 4:
a + 2
------------------
a(a + 2)(a - 2)

Cancel like term:
1
--------
a(a - 2)

Was that clear, OH debbie honey?

 

[debbie29]

Ah!!! I SEE IT!
THANK YOU!!