Question

HELP!!!
Which polynomial is a perfect square trinomial?

A.9x2 - 12x + 4
B.36b2 - 24b + 16
C.16x2 - 24x - 9
D.4a2 - 10a - 25

Answer 1

Let me take you through the steps, okay?

Answer 2

ok

Answer 3

For a perfect square trinomial, the first and last terms should always be able to have perfect square roots (i.e., 2 x 2 = 4, 3 x 3 = 9, etc.). The middle term should be what happens when you multiply the first term by the third (i.e., 2 x 3 = 6).

Let's use an example, shall we?

4x^2 + 6x + 9.

Answer 4

What is the square root of 4x^2 and the square root of 9?

Answer 5

If you don't know what a square root is, it's basically like that 2 x 2 = 4 example I gave earlier. It's a number times itself. Another example for that would be 5 x 5 = 25.

Answer 6

I'm waiting for your answer. What is the square root of 4x^2? Do you need me to show you that?

Answer 7

is it 5?

Answer 8

No. Think about this:
What can four be divided into?

Answer 9

Really? Please don't tell me that you closed this because you don't know what four divides into and had to ask that.

Answer 10

Four can be divided into 4 x 1 and 2 x 2, without using decimals. So, which creates a square? Think, two sides with four and one, or four sides sides with two?

Answer 11

The correct answer to that would be 2. As in, 2 x 2 = 4.

Answer 12

So, to get 4x^2, you'd have to do this:
2x times 2x, which would make 2 x 2 = 4 and x times x = x^2.

Answer 13

Do you understand?