(7x + 4)(7x + 4) and (x – 9)(x – 9) are Perfect square trinomial. (5x + 3)(5x – 3) and (–3x – 6)(–3x + 6) shows the Difference of squares.
<h3>What is a perfect square?</h3>
A perfect square is a number system that can be expressed as the
square of a given number from the same system.
The following are the answers
(5x + 3)(5x – 3) Difference of squares
(7x + 4)(7x + 4) is a Perfect square trinomial
(2x + 1)(x + 2) has Neither a difference of squares nor a perfect square trinomial.
(4x – 6)(x + 8) has Neither a difference of squares nor a perfect square trinomial.
(x – 9)(x – 9) is Perfect square trinomial
(–3x – 6)(–3x + 6) = 
Difference of squares.
Learn more about perfect square:
brainly.com/question/1415730
Answer:
20.25 pi
Step-by-step explanation:
The circumference of a circle is given by
C = 2 * pi *r
9 pi = 2 * pi *r
Divide each side by 2pi
9pi / 2 pi = 2 pi r / 2 pi
4.5 = r
Now we can find area
A = pi r^2
= pi ( 4.5)^2
20.25 pi
<h3>
Answer: Choice B</h3><h3>
y = x^2 + 7x + 1</h3>
======================================
Proof:
A quick way to confirm that choice B is the only answer is to eliminate the other non-answers.
If you plugged x = 1 into the equation for choice A, you would get
y = -x^2 + 7x + 1
y = -1^2 + 7(1) + 1
y = -1 + 7 + 1
y = 7
We get a result of 7, but we want 9 to be the actual output. So choice A is out.
-----------
Repeat for choice C. Plug in x = 1
y = x^2 - 7x + 1
y = 1^2 - 7(1) + 1
y = 1 - 7 + 1
y = -5
We can eliminate choice C (since again we want a result of y = 9)
-----------
Finally let's check choice D
y = x^2 - 7x - 1
y = 1^2 - 7(1) - 1
y = 1 - 7 - 1
y= -7
so choice D is off the list as well
-----------
The only thing left is choice B, so it must be the answer. It turns out that plugging x = 1 into this equation leads to y = 9 as shown below
y = x^2 + 7x + 1
y = 1^2 + 7(1) + 1
y = 1 + 7 + 1
y = 9
And the same applies to any other x value in the table (eg: plugging in x = 3 leads to y = 31, etc etc).
Answer:
i dont know for shore but i think it is part 2
Step-by-step explanation:
