Question

Bob would like to create a triangle that is seven less than twice the perimeter of the triable below. Give an expression of the perimeter of the new triangle.

Answer 1

`14y + 9`

Explanation:

Perimeter of the triangle =
`(y + 9) + 2y + (4y - 1)`

`y + 9 + 2y + 4y - 1`

Combine like terms

`y + 2y + 4y + 9 - 1`

`Perimeter = 7y + 8`

If Bob creates a new triangle whose perimeter is 7 less than twice the perimeter of the given triangle, the expression for the perimeter of the new triangle would be:

Twice of the perimeter = 2(7y + 8)

7 less than twice the perimeter = 2(7y + 8) - 7

Simplify the expression

New perimeter =
`2(7y + 8) - 7`

=
`2*7y + 2*8 - 7` (distributing 2)

`= 14y + 16 - 7`

New perimeter
`= 14y + 9`