Question

Help, please?

Which polynomial is a perfect square trinomial?

49x2 − 28x + 16
4a2 − 20a + 25
25b2 − 20b − 16
16x2 − 24x − 9

Answer 1

find the square root of the first and last terms and try to combine them to get the middle term

Answer 2

* first and last coefficients I should have said

Answer 3

(a + b^2 = a^2 + 2ab + b^2

a and b have to such that they can form 2ab

Answer 4

I want to say B but I'm not sure-

Answer 5

the last 2 option are incorrect because there are no real square roots of -16 and -9

Answer 6

what are the square roots of 2a^2 and 25

Answer 7

* 4a^2 and 25?

Answer 8

remember that 25 = 5*5 or -5*-5

Answer 9

The square root of 25 is 5, but I'm not sure about 4a^2

Answer 10

2a * 2a = 4a^2

Answer 11

sqrt 25 is 5 OR -5

Answer 12

Okay, that makes sense, so wait would the square root of 4a^2 be 2a?

Answer 13

so if a = 2a and b = -5 what is the value of 2ab?

Answer 14

yes

Answer 15

So it would be 2a*5 since b=5?

Answer 16

Or -5 I should say.

Answer 17

no
2 * 2a * -5

Answer 18

what does that come to?

Answer 19

2a*25, right? Since you really can't do anything with the A right now because we don't know what that is-

Answer 20

NONO NEVERMIND
2a*10

Answer 21

2a * -10

Answer 22

its NEGATIVE 5 here because the middle term is negative

Answer 23

Oh, okay. That makes more sense.

Answer 24

so what does 2*-10a simplify to?

Answer 25

-20a?

Answer 26

I think that's right at least-