Math Problem Statement

Given the area of a rectangle as 8a^2 + 18a - 6 and the width as 4a - 2, find the length of the rectangle. (Show solution by presenting the formula of the area of a rectangle and using Long Division).

Solution

The image shows a mathematical problem asking to find the length of a rectangle, given its area and width.

The problem can be summarized as follows:

  • Area of the rectangle: 8a2+18a68a^2 + 18a - 6
  • Width of the rectangle: 4a24a - 2
  • The task is to find the length by using the formula for the area of a rectangle and applying long division.

Solution:

We know the formula for the area of a rectangle is:

Area=Length×Width\text{Area} = \text{Length} \times \text{Width}

Given:

  • Area: 8a2+18a68a^2 + 18a - 6
  • Width: 4a24a - 2

To find the length, we divide the area by the width using polynomial long division:

Length=8a2+18a64a2\text{Length} = \frac{8a^2 + 18a - 6}{4a - 2}

I'll now perform the long division to find the length.

Long Division Steps:

  1. Divide the leading term of the numerator 8a28a^2 by the leading term of the denominator 4a4a, which gives 2a2a.

  2. Multiply 2a2a by the entire divisor 4a24a - 2, which results in 8a24a8a^2 - 4a.

  3. Subtract (8a24a)(8a^2 - 4a) from (8a2+18a6)(8a^2 + 18a - 6), leaving 22a622a - 6.

  4. Divide the new leading term 22a22a by 4a4a, which gives +5.5+5.5 (or +112+\frac{11}{2}).

  5. Multiply 5.55.5 by 4a24a - 2, resulting in 22a1122a - 11.

  6. Subtract (22a11)(22a - 11) from (22a6)(22a - 6), resulting in 55.

Thus, the quotient (length) is 2a+5.52a + 5.5, with a remainder of 5.

This gives:

Length=2a+112with a remainder of 5.\text{Length} = 2a + \frac{11}{2} \quad \text{with a remainder of 5.}

This represents the length of the rectangle based on the division process.


Do you want more details on the long division steps, or do you have any other questions?

Related Questions:

  1. How is polynomial long division different from regular long division?
  2. Can the remainder in polynomial division always be interpreted geometrically?
  3. How do you simplify polynomials before dividing them?
  4. What other methods, besides long division, can be used to divide polynomials?
  5. How can we check the result of polynomial division?

Tip:

Always check your result by multiplying the quotient and the divisor back together to ensure they produce the original dividend.

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Math Problem Analysis

Mathematical Concepts

Algebra
Polynomial Division
Rectangles
Area Formulas

Formulas

Area of a rectangle = Length × Width
Polynomial Long Division

Theorems

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Suitable Grade Level

Grades 9-12