AnswersFL-1200330-Algebra 2 ACompleting The Square

Lesson 3.4: Completing The Square Answers

25 verified answers1 views
1
Free Preview

Which of the following expressions are perfect-square trinomials? Check all of the boxes that apply.

A
x2 – 16x – 64
B
4x2 +12x + 9
C
x2 + 20x + 100
D
x2 + 4x + 16
4

A student says that if 5x2 = 20, then x must be equal to 2. Do you agree or disagree with the student? Justify your answer.

Answer:

I disagree with the student. While 2 is a solution, it is not the only possible value for x. Dividing both sides of the equation 5x^2 = 20 by 5 results in x^2 = 4. According to the square root property, taking the square root of both sides gives x = 2 or x = -2. Therefore, x could be -2 as well.

5

Compare your response with the sample response presented here. Did your explanation

A
mention the square root property?
B
say that x could also be –2?
9

Now, write x² - 16x + 64 = -8 as (x - 8)² = -16✔ (x - 8)² = -8(x - 16)² = -16(x - 16)² = -8

A
(x - 8)² = -16
B
✔ (x - 8)² = -8
C
(x - 16)² = -16
D
(x - 16)² = -8
10

.

Question illustration
Answer:

2

11

⇒ 8

Question illustration
Answer:

8

14

=

Answer:

-13

16

–13 +

Answer:

9

18

=

Answer:

-4

Did you find these answers helpful?