The length of the first square is 1cm more than twice the length of the second side, and the difference of their circumference is 24cm. Find the area of two squares {equation} The distance between the two places is 900m. Xiaohong and Xiaomei set out at the same place at the same time. Xiaohong every minute is 80m. Xiaomei every minute is 100m. When Xiaomei arrived at the destination, she immediately went back along the original road to meet Xiaohong. How many hours did it take them

The length of the first square is 1cm more than twice the length of the second side, and the difference of their circumference is 24cm. Find the area of two squares {equation} The distance between the two places is 900m. Xiaohong and Xiaomei set out at the same place at the same time. Xiaohong every minute is 80m. Xiaomei every minute is 100m. When Xiaomei arrived at the destination, she immediately went back along the original road to meet Xiaohong. How many hours did it take them

Let's say they've been through X minutes
100x+80x=900X2
x=10

A square with a side length of 10 cm. If you cut a small square with a side length of 1 cm from all four corners, its perimeter will be ()
A. Increase 4cm B. decrease 4cm C. unchanged

As shown in the figure above, after cutting a small square ABCD, the lengths of AB and AC are cut off, but the lengths of BD and CD are added, and ab = CD = BD = AC is the same as cutting a square at the other three corners, so the perimeter of the later figure is equal to the original perimeter; so select: C