Math Problem Statement

Write an equation that can be used to solve for x if the perimeter of the rectangle below is 384 inches.

Solution

The problem asks for the equation to solve for xx when the perimeter of the rectangle is 384 inches.

Step 1: Identify the sides of the rectangle.

  • The length of the rectangle is given as 5(3x9)5(3x - 9).
  • The width of the rectangle is given as 2(8x4)2(8x - 4).

Step 2: Formula for the perimeter of a rectangle.

The perimeter PP of a rectangle is calculated using the formula: P=2×(Length+Width)P = 2 \times (\text{Length} + \text{Width})

Step 3: Substitute the given expressions into the formula.

P=2×[5(3x9)+2(8x4)]P = 2 \times \left[5(3x - 9) + 2(8x - 4)\right]

Step 4: Set the perimeter equal to 384 inches.

2×[5(3x9)+2(8x4)]=3842 \times \left[5(3x - 9) + 2(8x - 4)\right] = 384

Step 5: Solve the equation.

  1. Distribute the constants inside the parentheses: 5(3x9)=15x455(3x - 9) = 15x - 45 2(8x4)=16x82(8x - 4) = 16x - 8
  2. Combine like terms: 2×(15x45+16x8)=3842 \times (15x - 45 + 16x - 8) = 384 2×(31x53)=3842 \times (31x - 53) = 384
  3. Divide both sides by 2: 31x53=19231x - 53 = 192
  4. Solve for xx: 31x=192+5331x = 192 + 53 31x=24531x = 245 x=245317.9x = \frac{245}{31} \approx 7.9

None of the multiple-choice answers seem to match this result exactly. It is possible that the correct answer was not simplified properly or involves an approximation. However, based on standard calculation, x7.9x \approx 7.9.

Would you like more details on how to interpret the problem further, or do you have any other questions?


Here are some related questions you might find helpful:

  1. How do you calculate the perimeter of other geometric shapes?
  2. What are common mistakes to avoid when solving perimeter problems?
  3. How do you solve quadratic equations derived from geometry problems?
  4. Can you explain the concept of distributing and combining like terms?
  5. How do you handle decimal approximations in perimeter calculations?

Tip: Always double-check your work by substituting your solution back into the original equation to see if it satisfies the given condition.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebra
Geometry
Linear Equations

Formulas

Perimeter of a rectangle: P = 2(L + W)

Theorems

-

Suitable Grade Level

Grades 8-10