Question

Which of the following represents a perfect square trinomial?

9x2 + 24x + 16

x2 + 8x – 16

x2 + 8x + 32

x2 + 8x + 36

Answer 1

@ParthKohli

Answer 2

Do you know factoring, Lou?

Answer 3

Yeah.

Answer 4

Can you factor all the four expressions?

Answer 5

Probably yeah.

Answer 6

Can you factor all and list them down? :)

Answer 7

K give me a sec. :)

Answer 8

Hey wait, for factoring. It's 2 numbers that when multiplied equal the last number, and add up to the middle one right?

Answer 9

I'd give you example for the fourth one.

x^2 + 8x + 36

We need to find two numbers that add up to 8 and multiply to get 36.
6 * 6 = 36
4 * 9 = 36
12 * 3 = 36

But there are no numbers we can find so x^2 + 8x + 36 is prime.

Answer 10

oh okay yeah. Lol was spooked for a sec. wasn't thinking about prime's. :)

Answer 11

Another way to determine these is to find the discriminant.

Answer 12

Leave that method.

Answer 13

K, I'm thinking they're all prime.

Answer 14

Let's try to factor 9x^2 + 24x + 16
16 * 9 = 144
We will now try to find two numbers that multiply to get 144 and add to get 24.

12 * 12 = 144
12 + 12 = 24

So now we split the middle term.

9x^2 + 12x + 12x + 16
Factor out 3x from first two and last two.

3x(3x + 4) + 4(3x + 4)

Group them to finish with

(3x + 4)(3x + 4)

Answer 15

K. and that would be the answer cause it's (3x+4)^2

Answer 16

(3x + 4)(3x + 4) is the same as (3x + 4) x (3x + 4) and when you multiply two numbers that are the same then you can write it as a perfect square.

Answer 17

Yep! :)

Answer 18

Tyvm @ParthKohli and sry if it took a while :)

Answer 19

Haha lol no