Question

I think its B not sure though...

Answer 1

Determine which polynomial is a perfect square trinomial.

\(36x^2 - 18x - 9\)
\(4a^2 - 28a - 49\)
\( 25b^2 - 20b + 4\)
\( 4x^2 - 6x + 9\)

Answer 2

Or D

Answer 3

Isnt it like the first and last term need to be positive?

Answer 4

Or is it A
So Confused /.\

Answer 5

Well
The square root of 36 is 6
square root of 9 is 3
6 + 3 is 9
9 times 2 is 18

But doesnt the last number need to be positive?

Answer 6

This is what you do. To have a perfect square trinomial you need this:
1. The first term must be positive and a perfect square.
2. The last term must be positive a perfect square.
3. Look at the sign of the middle term. If it is positive, use the positive square root of the third term in step 4. If it is negative, use the negative square root of the third term in step 4.
3. Take the square roots of the first term and of the last term, multiply them together and by 2. If that is the 2nd term it is a perfect square binomial.

Answer 7

Yes, the first and third terms must be positive.

Answer 8

So then...
Its either D or C, since both have the last terms as positive
When you take the square root of 25 you get 5
Square root of 4 is 2
5 times 2 = 10
10 times 2 equals 20
So it would be C right?
c:

Answer 9

I hope i did it right /.\

Answer 10

Yes, you are correct.

Answer 11

Thank You so much
You helped me understand c:

Answer 12

You are welcome.