these is my homework, and I would like for some to tell me if I did rigth.

10. A rentangle has width the same as a side of a square whose perimeter is 20m. the length of the rectangel is 9 M. Find the perimeter of this rectangle.
W=L+20m

2L+w=9
2L+2w(w-18)=84
2L+2w-18=84
4L+18=84
4L=18-84
4L=66
L=66/4

Each side of the square must be 5 m (20/4).
The rectangle's measurements are 5 m x 9 m.
P = 2W + 2L
P = 10 + 18
P = ____________

To check if you did the problem correctly, let's go through it step by step.

1. You started by saying that the width of the rectangle is the same as one side of the square, which has a perimeter of 20m. This means each side of the square is 20/4 = 5m. This step is correct.

2. You then calculated the length of the rectangle using the equation 2L + w = 9. Since w = 5m, the equation becomes 2L + 5 = 9. Solving for L gives L = (9 - 5)/2 = 4/2 = 2m. This step is correct.

3. Next, you wrote the equation 2L + 2w(w-18) = 84. It seems like you made a mistake here. The formula for the perimeter of a rectangle is P = 2L + 2w, so the correct equation would be 2(2) + 2(5) = 4 + 10 = 14. Therefore, the perimeter of this rectangle is 14m.

So, based on your calculations, it looks like you made an error in step 3, so the final answer for the perimeter should be 14m, not 84m as you originally had.

Please note that I have made the assumption that the formula you used in step 3 was meant to calculate the perimeter rather than solving for another variable. If you can provide clarification on that, I can give a more accurate response.