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Clara writes the equation (x – 13)(x + 8) = 196 to solve for the missing side length of a rectangle represented by the factor x + 8. What is the missing side length represented by x + 8 units of the rectangle? 7 15 20 28

User Xanld
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2 Answers

6 votes

The Answer is 28.



Clara writes the equation (x – 13)(x + 8) = 196 to solve for the missing side length of a rectangle represented by the factor x + 8. What is the missing side length represented by x + 8 units of the rectangle?

User Antho Christen
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8.1k points
5 votes

First, we are going to solve the equation
(x-13)(x+8)=196 to find the value of
x.

Let's solve the equation step by step

Step 1. Use the distributive property to destroy the parenthesis:


(x-13)(x+8)=196


x^2+8x-13x-104=196


x^2-5x-104=196

Step 2. Subtract 196 to both sides of the equation:


x^2-5x-104-196=196-196


x^2-5x-300=0

Step 3. Factor the expression:


(x+15)(x-20)=0

Step 4. Set each factor equal to zero and solve for
x:


x+15=0 or
x-20=0


x=-15 or
x=20

Since we are dealing with lengths here, and lengths cannot be negative, the only valid solution is
x=20

Now, we know from our problem that the missing side of the rectangle is given by the expression
x+8, so to find the actual length, we just need to replace
x with 8 in the given expression and simplify:


Missing.Length=x+8


Missing.Length=20+8


Missing.Length=28 units

We can conclude that the missing side length represented by x + 8 units of the rectangle is 28 units.

User Exel
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7.8k points