The width of the rug is 3 inches
Step-by-step explanation:
A knitter wants to make a rug for a dollhouse
- The length of the rug will be 2 inches more than it’s width
- The total area of the rug ( in square inches) based on the width w of the rug (in inches ) is given by A(w) = w (2 + w)
- The desired area of the rug is 15 square inches
We need to find the width of the rug
∵ The area of the rug is A(w) = w(2 + w)
- Simplify the right hand side
∴ A(w) = 2w + w²
∵ The desired area of the rug is 15 square inches
- Equate A(w) by 15
∴ 2w + w² = 15
- Subtract 15 from both sides
∴ 2w + w² - 15 = 0
- Its a quadratic equation arrange its terms from the greatest power of x
∴ w² + 2w - 15 = 0
Factorize it into two binomial factors
∵ w² = w × w
∵ 15 = 3 × 5
∵ 5w - 3w = 2w
∴ w² + 2w - 15 = (w -3)(w + 5)
∴ (w - 3)(w + 5) = 0
- Equate each factor by 0
∴ w - 3 = 0 OR w + 5 = 0
∵ w - 3 = 0
- Add 3 to both sides
∴ w = 3
∵ w + 5 = 0
- Subtract 5 from both sides
∴ w = -5 ⇒ rejected because no dimension with -ve value
∴ w = 3 only
The width of the rug is 3 inches
Learn more:
You can learn more about the quadratic equation in brainly.com/question/9328925
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