232k views
5 votes
I am confused see image

I am confused see image-example-1
User Sibidharan
by
8.4k points

1 Answer

5 votes

Answer: 80, 80

Explanation:

The perimeter of a rectangle/square formula:

2L+2w=P >P=320

2L+2w=320 >solve for one of variables let's pick L

2L = 320 - 2w

L = (320 - 2w)/2 >Simplify the dividing by 2

L = 160-w

You also need Area formula:

A = L(w) >Substitute from what we found from Perimeter

formula

A = (160-w)(w) >Distribute w

A = 160w - w² >Maximum are happens at the vertex of this

quadratic

A = w² - 160w

Vertex x formula in (x, y) for vertex:

a=1 b= -160 from A = w² - 160w from standard form: ax²+bx+c


w =- (b)/(2a)\\\\w= - (-160)/(2(1))

w=80

Substitute back into Perimeter to find L

L = 160-w

L = 160 - 80

L = 80

User Peter Duijnstee
by
8.0k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories