Question 188326
I'm assuming that you want to factor this right?



Note: {{{4x^2+12x+9}}} is NOT a binomial, it is a trinomial.




Looking at the expression {{{4x^2+12x+9}}}, we can see that the first coefficient is {{{4}}}, the second coefficient is {{{12}}}, and the last term is {{{9}}}.



Now multiply the first coefficient {{{4}}} by the last term {{{9}}} to get {{{(4)(9)=36}}}.



Now the question is: what two whole numbers multiply to {{{36}}} (the previous product) <font size=4><b>and</b></font> add to the second coefficient {{{12}}}?



To find these two numbers, we need to list <font size=4><b>all</b></font> of the factors of {{{36}}} (the previous product).



Factors of {{{36}}}:

1,2,3,4,6,9,12,18,36

-1,-2,-3,-4,-6,-9,-12,-18,-36



Note: list the negative of each factor. This will allow us to find all possible combinations.



These factors pair up and multiply to {{{36}}}.

1*36
2*18
3*12
4*9
6*6
(-1)*(-36)
(-2)*(-18)
(-3)*(-12)
(-4)*(-9)
(-6)*(-6)


Now let's add up each pair of factors to see if one pair adds to the middle coefficient {{{12}}}:



<table border="1"><th>First Number</th><th>Second Number</th><th>Sum</th><tr><td  align="center"><font color=black>1</font></td><td  align="center"><font color=black>36</font></td><td  align="center"><font color=black>1+36=37</font></td></tr><tr><td  align="center"><font color=black>2</font></td><td  align="center"><font color=black>18</font></td><td  align="center"><font color=black>2+18=20</font></td></tr><tr><td  align="center"><font color=black>3</font></td><td  align="center"><font color=black>12</font></td><td  align="center"><font color=black>3+12=15</font></td></tr><tr><td  align="center"><font color=black>4</font></td><td  align="center"><font color=black>9</font></td><td  align="center"><font color=black>4+9=13</font></td></tr><tr><td  align="center"><font color=red>6</font></td><td  align="center"><font color=red>6</font></td><td  align="center"><font color=red>6+6=12</font></td></tr><tr><td  align="center"><font color=black>-1</font></td><td  align="center"><font color=black>-36</font></td><td  align="center"><font color=black>-1+(-36)=-37</font></td></tr><tr><td  align="center"><font color=black>-2</font></td><td  align="center"><font color=black>-18</font></td><td  align="center"><font color=black>-2+(-18)=-20</font></td></tr><tr><td  align="center"><font color=black>-3</font></td><td  align="center"><font color=black>-12</font></td><td  align="center"><font color=black>-3+(-12)=-15</font></td></tr><tr><td  align="center"><font color=black>-4</font></td><td  align="center"><font color=black>-9</font></td><td  align="center"><font color=black>-4+(-9)=-13</font></td></tr><tr><td  align="center"><font color=black>-6</font></td><td  align="center"><font color=black>-6</font></td><td  align="center"><font color=black>-6+(-6)=-12</font></td></tr></table>



From the table, we can see that the two numbers {{{6}}} and {{{6}}} add to {{{12}}} (the middle coefficient).



So the two numbers {{{6}}} and {{{6}}} both multiply to {{{36}}} <font size=4><b>and</b></font> add to {{{12}}}



Now replace the middle term {{{12x}}} with {{{6x+6x}}}. Remember, {{{6}}} and {{{6}}} add to {{{12}}}. So this shows us that {{{6x+6x=12x}}}.



{{{4x^2+highlight(6x+6x)+9}}} Replace the second term {{{12x}}} with {{{6x+6x}}}.



{{{(4x^2+6x)+(6x+9)}}} Group the terms into two pairs.



{{{2x(2x+3)+(6x+9)}}} Factor out the GCF {{{2x}}} from the first group.



{{{2x(2x+3)+3(2x+3)}}} Factor out {{{3}}} from the second group. The goal of this step is to make the terms in the second parenthesis equal to the terms in the first parenthesis.



{{{(2x+3)(2x+3)}}} Combine like terms. Or factor out the common term {{{2x+3}}}



{{{(2x+3)^2}}} Condense the terms.



---------------------------------------------



Answer:



So {{{4x^2+12x+9}}} factors to {{{(2x+3)^2}}}.



Note: you can check the answer by FOILing {{{(2x+3)^2}}} to get {{{4x^2+12x+9}}} or by graphing the original expression and the answer (the two graphs should be identical).