Question

The length of a rectangle is twice the width. The perimeter is 25. The system to help find the length and width is:

L=2W

2L+2W=25

Aaron tried using a graph to find the measurements but was unsure of the exact values. Use substitution to solve the system exactly. Round to the nearest hundreth.

Answer 1

Let the width be x
Since the question mentions the length is twice the width,
let the length be 2x
The total perimeter given is 25cm and as we know, perimeter for a rectangle :
=> P = 2(Length + width)
So,

25cm = 2(2x + x)
25 = 4x + 2x
25 = 6x
25/6 = x
4.166666667 = x

Answer 2

9514 1404 393

Answer:

(L, W) ≈ (8.33, 4.17)

Explanation:

Substituting for L, we have ...

2(2W) +2W = 25

6W = 25

W = 25/6 ≈ 4.17

L = 25/3 ≈ 8.33

The rounded "exact" solution is ...

(L, W) = (8.33, 4.17)