Math Problem Statement

find value of x (round answer to the nearest hundredth if neccesary) when base of rectangle=(2x+10) and height of rectangle=(3x), area of rectangle=288 inches squared

Solution

The area of a rectangle is given by the formula: Area=Base×Height.\text{Area} = \text{Base} \times \text{Height}.

Given:

  • Base = 2x+102x + 10
  • Height = 3x3x
  • Area = 288 square inches

Substitute the given values into the formula: 288=(2x+10)×(3x).288 = (2x + 10) \times (3x).

Expand the right-hand side: 288=6x2+30x.288 = 6x^2 + 30x.

Now, rearrange this into a standard quadratic equation: 6x2+30x288=0.6x^2 + 30x - 288 = 0.

To simplify this equation, divide all terms by 6: x2+5x48=0.x^2 + 5x - 48 = 0.

Now, solve this quadratic equation using the quadratic formula: x=b±b24ac2a,x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}, where a=1a = 1, b=5b = 5, and c=48c = -48.

Substitute these values into the formula: x=5±524×1×(48)2×1,x = \frac{-5 \pm \sqrt{5^2 - 4 \times 1 \times (-48)}}{2 \times 1}, x=5±25+1922,x = \frac{-5 \pm \sqrt{25 + 192}}{2}, x=5±2172.x = \frac{-5 \pm \sqrt{217}}{2}.

Calculate the square root of 217 and simplify: x=5±14.732.x = \frac{-5 \pm 14.73}{2}.

This gives two possible values for xx: x=5+14.732=9.7324.87,x = \frac{-5 + 14.73}{2} = \frac{9.73}{2} \approx 4.87, x=514.732=19.7329.87.x = \frac{-5 - 14.73}{2} = \frac{-19.73}{2} \approx -9.87.

Since xx represents a length, it must be positive. Thus, the value of xx is approximately: x4.87.x \approx 4.87.

Would you like more details or have any questions about this solution?

Here are 5 related questions for further exploration:

  1. What is the perimeter of the rectangle with the found value of xx?
  2. What are the dimensions of the rectangle when x4.87x \approx 4.87?
  3. How would the problem change if the area of the rectangle were different?
  4. What would the quadratic equation look like if the base and height expressions were swapped?
  5. How does the quadratic formula help in solving problems like this?

Tip: Always check the feasibility of solutions in real-world contexts, like ignoring negative values for dimensions.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Equations
Geometry

Formulas

Area of a rectangle: Area = Base × Height
Quadratic equation: ax^2 + bx + c = 0
Quadratic formula: x = (-b ± √(b² - 4ac)) / 2a

Theorems

Quadratic Formula

Suitable Grade Level

Grades 8-10