IDNStudy.com, kung saan ang iyong mga tanong ay may malinaw na sagot. Anuman ang kahirapan ng iyong mga tanong, ang aming komunidad ay may mga sagot na kailangan mo.

The area of a rectangular room is 65m2. Find the perimeter of the room given that its length is 3m more than thrice its width.
Using quadratic equation

Sagot :

The area of a rectangle is given by the formula: A = lw

Given that its length is 3m more than thrice its width you'll have:

l = 3w + 3 -----equation1 

and

A = 65m²

Substitute everything to the area formula you'll have:

A = lw65m² = (3w + 3 ) (w)

65 = 3w² + 3w  or

3w² + 3w - 65 = 0

using quadratic formula you'll have:

[tex]w = \frac{-b (+-) \sqrt{b^2-4ac} }{2a} \\ w = \frac{-3(+-) \sqrt{3^2-4(3)(-65)} }{2(3)} \\ w = \frac{-3 (+-) \sqrt{789} }{6} \\ w= \frac{-3 + \sqrt{789} }{6} = 4.1815; \\ w= \frac{-3- \sqrt{789} }{6}=-5.1815 [/tex]

take the positive value since there's no negative length.

w = 4.1815m

substitute to equation 1

l = 3w + 3

l = 3(4.1815) + 3

l = 15.5445m

Since you are asked of the perimeter then you'll have the formula for perimeter of a rectangle used.

P = 2l + 2w

Substituting you'll have:

P = 2 (15.5445) + 2(4.1815)

P = 39.452meters