Final answer:
To find the dimensions of Marianne's scarf, we set up a quadratic equation with the width as 'w' and solved to determine the width is 7 inches and the length is 12 inches.
Step-by-step explanation:
The students question involves finding the dimensions of Marianne's scarf given that the scarf's length is 5 inches longer than its width and that it has an area of 84 square inches. We can set up an equation to solve this problem.
Let's denote the width of the scarf as w inches. Then, the length of the scarf would be w + 5 inches. We know that Area = Length × Width, so we can write the equation:
84 = w × (w + 5)
To solve for w, we need to find the values of w that satisfy the equation, which is a quadratic equation that can be solved by factoring, completing the square, or using the quadratic formula. After solving, we get that the width of the scarf is 7 inches and the length is 12 inches.