A rectangle with an area of 81 cm² has a length that is 3 times the width. How long is the width of the rectangle? Round to the

Question

2 years ago

11

nearest tenth.

2 answers:

iren2701 [21] · Answer 1 · 2022-09-18T02:44:50+03:00

4 0

Answer:

60.75 ≈ 60.8

Step-by-step explanation:

4u-> 81

1u -> 20.25 (width)

3u-> 60.75 (length)

LenaWriter [7] · Answer 2 · 2022-09-18T01:10:38+03:00

Answer:

W ≈ 5.2 cm

Step-by-step explanation:

Represent the length and width by L and W respectively.

Then L * W = 81 cm^2, and L = 3W.

Substituting 3W for L in the first equation, we get:

3W * W - 81 = 0, or 3W^2 - 81 = 0.

To make it easier to find the final answer, rewrite 3W^2 - 81 = 0 as

81

W^2 = ------- = 27

3

Then W (the width) is the positive square root of 27, or W ≈ 5.2 cm