Answer:
d.
but if you think the answer is not d
you may look at this
↓↓
↓↓
↓↓
Step-by-step explanation:
You can easily find it by factoring.
4x2+12x+9
We find two numbers that multiply to get 36, but add to get 12.
These terms are, 6 and 6
6∗6=36
6+6=12
So, we use these terms and replace them with 12x
4x2+6x+6x+9
We factor out the first two terms
4x2=2∗2∗x∗x
6x=2∗3∗x
We can see that they both share a factor of 2x
So, we write it as 2x(2x+3)
Now, we factor out the next two terms.
6x=2∗3∗x
9=3∗3
We can see that these two have a common factor of 3 .
So, we write it as 3(2x+3)
We put the two together 2x(2x+3)+3(2x+3)
We add them and get (2x+3)(2x+3)
In other words, the length is 2x+3
