SOLUTION: Please help me expand and simplify this: (2x+3)^2+3(x+1)^2. I tried expanding it- but failed to do so. I'm not sure of how to solve this problem but know that the answer is: 7x^2+

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Question 627699: Please help me expand and simplify this: (2x+3)^2+3(x+1)^2.
I tried expanding it- but failed to do so. I'm not sure of how to solve this problem but know that the answer is: 7x^2+18x+12. When I tried solving it, I got: 5x^2+9x+12. Here are my steps:
Expand and Simplify: (2x+3)^2+3(x+1)^2
1. 2x^2+6x+9+3[x^2+x+1]
For step 1, I multiplied 2x by the power of 2 which i got: 2x^2, then three times 2 which i got 6x and then i multiplied 3 times 3, which i got 9.
2. 2x^2+6x+9+3x^2+3x+3
I then multiplied 3 times x^2 which i got 3x^2, then i multiplied 3 times x, which i got 3x and then i multiplied 3 times 1 which is three.
Lastly, I gathered the like terms and did steps according to the negative and positive terms and as an answer, I got: 5x^2+9x+12.
Found 2 solutions by ewatrrr, solver91311:
Answer by ewatrrr(24785)   (Show Source): You can put this solution on YOUR website!
 

Hi,

(2x+3)^2 +3(x+1)^2

1. x^2+x+9 + 3[x^2+x+1]  

   7x^2 + 18x + 12

Note:

(2x+3)^2 = (2x+3)(2x+3)

 F	First terms  4x^2

O	Outside terms 6x

I	Inside terms  6x

L	Last terms    9

 

 (x+1)^2 = (x+1)(x+1)

F	First terms  x^2

O	Outside terms x

I	Inside terms  x

L	Last terms    1

  

Answer by solver91311(24713)   (Show Source): You can put this solution on YOUR website!
 





Your step 1 is incorrect.  Write it out in expanded form and then use FOIL.  Firsts:   times .  Outsides:   times .  Insides:  times .  Lasts:  times  











Then











Now add like terms:









John



My calculator said it, I believe it, that settles it


The Out Campaign: Scarlet Letter of Atheism


 

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