SOLUTION: How do i work this one out and then factor it? please help. 4(a + 3)2 � (a + 3) � 18

Question 731867: How do i work this one out and then factor it? please help.
4(a + 3)2 � (a + 3) � 18
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
How do i work this one out and then factor it? please help.
4(a + 3)2 � (a + 3) � 18
=========================
I don't know what you mean by "work this one out," but it can be factored
----
Use ^ (Shift 6) for exponents
4(a + 3)^2 � (a + 3) � 18
sub x for (a+3) temporarily
4x^2 � x � 18
It will be either (x + m)*(4x + n) or (2x + m)*(2x + n)
Since the x term has an odd coefficent, it can't be (2x + m)*(2x + n).
-------------
It will be (x + m)*(4x + n)
Find a pair of factors of 18 that fit.
The signs will be different since it's -18
---
18 has 3 pairs of factors
1*18
2*9
3*6
----
(x + m)*(4x + n)
The n has to be the odd number, so it's 1, 3 or 9 (either + or minus)
Now it's trial and error.
(x + 2)*(4x - 9) works
=============================
Sub back (a+3) for x
= (a+3+2)*(4a+12-9)
= (a+5)*(4a+3)
******************************
You can expand 4(a + 3)^2 � (a + 3) � 18 first
= 4a^ + 24a + 36 - a - 3 - 18
= 4a^2 + 23a + 15
That might be slightly easier since it's all positive numbers.

RELATED QUESTIONS
I have been working on this math problem and I got to working on it. Well, then I got... (answered by stanbon)

How do I factor this out 6x^3>7x^2+3x (this is a polynomial and rational inequality) ??? (answered by Edwin McCravy)

5/6+7/18 divided by 3/2 I need help solving this problem. I can't remember how to work... (answered by Cromlix)

I am having problems with a problem. The problem is ax^2 + bx + c. Would you please show... (answered by josgarithmetic)

Could someone please check these, I am not sure if I understood them correctly. I should (answered by Alan3354)

Please help..how do i work this problem. I have to factor the numerator and denominator... (answered by AnlytcPhil)

Please help me factor this polynomial: {{{8x^3-12x^2+6x-1}}}. I am trying to figure out... (answered by ewatrrr,stanbon)

I am a parent trying to help my 8th grader. Could you please help me explain how to work... (answered by Linz)

Can you please help me factor this polynomial x^4+3.5x^3-6x^2-14x+8? I need it for a... (answered by Alan3354)