The length of a rectangle is twice its width. If the perimeter of the rectangle is 30 cm, find its length and width.

width - 5cm

length - 10cm

Step-by-step explanation:

Let's define the variable w as the width of the rectangle. The length of the rectangle would be 2w as given by the problem. A form of the perimeter of a rectangle formula is:

P = 2(l + w)

Where P is the perimeter, l is the length, and w is the width. We substitute our length, width, and perimeter to get:

30 = 2(2w + w)

You can simplify to get:

30 = 2(3w)

and divide by 6 on both sides to isolate w:

w = 5cm - the width is 5 cm

The length is twice the width, and 2 x 5 is 10, so 10cm is the length.

you didn't post any answer choices, so its not 100% clear what your teacher is looking for

however, log(15/7) is equivalent to log(15) - log(7)

i'm using the rule log(x/y) = log(x) - log(y)