Question

Michelle simplified an expression for the perimeter of the rectangle below and got 5/6x + 35. Explain her error, and include the correct expression for the perimeter.

The width is 5/6x+23 and the Height is 12.

Answer 1

Michelle didn't double the height and width for the perimeter and the correct expression is:

Explanation:

Given

Length = l = 5/6x+23

Width = w = 12

The perimeter of a rectangle is given by:

Putting the values, we get

The length and width had to be doubled for the perimeter which Michelle didn't.

Hence,

Michelle didn't double the height and width for the perimeter and the correct expression is:

Explanation:

Answer 2

Michelle didn't double the height and width for the perimeter and the correct expression is:

`(5)/(3)x+70`

Explanation:

Given

Length = l = 5/6x+23

Width = w = 12

The perimeter of a rectangle is given by:

`P = 2(l+w)`

Putting the values, we get

`P = 2\{((5)/(6)x+23)+12\}\\\\P = 2((5)/(6)x+23+12}\\P =2((5)/(6)x+35)\\P = 2*(5)/(6) + 2* 35\\P =(5)/(3)x+70`

The length and width had to be doubled for the perimeter which Michelle didn't.

Hence,

Michelle didn't double the height and width for the perimeter and the correct expression is:

`(5)/(3)x+70`