Question

A square garden has an area of 400 square feet. Each side of the garden is (x-10) feet in length.

Write an equation that represents the AREA of the garden

Find the value of x using the square root method

What is the length of the side of the garden?

Answer 1

400 = (x - 10)²

x² -20x -300 = 0

x = 30 and x = -10

Length side of the garden = 20 feet

Explanation:

Given:

Area of square garden = 400 square feet

Length side of the garden = (x - 10) feet

Find:

Length side of the garden

Computation:

Area of square = side²

Area of square garden = Length side of the garden²

400 = (x - 10)²

400 = x² -20x + 100

x² -20x -300 = 0

x² -30x + 10x -300 = 0

x(x - 30) + 10(x - 30) = 0

(x - 30)(x + 10) = 0

So,

x = 30 and x = -10

Use x = 30 positive number

Length side of the garden = (x - 10) feet

Length side of the garden = (30 - 10) feet

Length side of the garden = 20 feet