Algebra B 3.9 Test Retake

Question

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Question
POSSIBLE POINTS: 1
The perimeter of the shape below is 21x^2-5x+4
. Find the length of the missing side.

Responses 4x^2-8
4x^2+5
14x^2-12x+8
-14x^2+12x-8

Answer 1

To find the length of the missing side, we need to add up all the sides of the shape and set it equal to 21x^2-5x+4.

Given sides:
1. 4x^2-8
2. 4x^2+5
3. 14x^2-12x+8
4. Missing side

Adding up all sides:
(4x^2-8) + (4x^2+5) + (14x^2-12x+8) + (Missing side) = 21x^2-5x+4

Combining like terms:
22x^2 - 5x + 5 + (Missing side) = 21x^2 - 5x + 4

Solving for the missing side:
(Missing side) = 21x^2 - 5x + 4 - 22x^2 + 5x - 5
(Missing side) = -x - 1

Therefore, the length of the missing side is -x-1.