Question

Candy draws a square design with a side length of x inches for the window at the pet shop. She takes the design to the printer and asks for a sign that has an area of 16x2 – 40x + 25 square inches. What is the side length, in inches, of the pet shop sign? 4x + 5 4x – 5 8x + 5 8x – 5

Answer 1

correct answer is

B)4x – 5

Answer 2

The pet shop sign is modelled as a square. The area of the square is given as
`16x^(2)-40x+25`.

Technically we want to take a square root of this expression to find the length of one side of the square but we will check first whether factorising will give us equal roots


`16x^(2)-40x+25`

`16 x^(2) -20x-20x+25`

`4x(4x-5)-5(4x-5)`

`(4x-5)(4x-5)`

As we see that by factorising gives us
`(4x-5)^(2)` hence the side length of the square is
`4x-5`