A rectangle is divided into four small rectangles, three of which are 24 square centimeter, 30 square centimeter and 32 square centimeter respectively Find the area of the shadow rectangle Make the formula simple

Answer: this problem can be divided into several ways to find out the relationship between the length and width of each small rectangle, so as to find out the length and width of the fourth small rectangle and calculate the area
24=4×6
30=5×6
32=4×8
The two sides of the fourth small rectangle are 8 and 5 respectively, so its area is 8 × 5 = 40

If the length of a rectangular board is reduced by 4 decimeters, its area will be reduced by 24 square decimeters. At this time, the remaining part is just a square. How many square decimeters is the original rectangular area?

Rectangle's width: 24 △ 4 = 6 (decimeter), rectangle's length: 6 + 4 = 10 (decimeter), rectangle's area: 10 × 6 = 60 (square decimeter); answer: original rectangle's area is 60 square decimeter

The area of a rectangle is 625 square centimeters. If the length is reduced to 1 / 5 of the original and the width is expanded to 5 times of the original, the rectangle will become a square. What is the area of the square and the side length of the square?

Length × width = 625
When the length is reduced to 1 / 5 of the original, it is 1 / 5 × long, and when the width is expanded to 5 times of the original, it is 5 × wide
1 / 5 × length × 5 width = length × width, the area does not change
The area of a square is 625 square centimeters, 625 = 25 × 25
The side length of a square is 25 cm

The square with an area of 8 square decimeters is reduced by 1:2 and drawn on the figure. What is the area ratio of the square on the figure to the original rectangle?

Original area = 8
Later area = 8 × (1 / 2 × 1 / 2) = 2
So the area ratio is 8:2 = 4:1

If the length of a rectangle is increased by 2 meters and the width by 5 meters, then the area will be increased by 60 square meters. At this time, it will just become a square?

Let the side length of a square be x meters, X2 - (X-2) (X-5) = 60, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; x2-x2 + 7x-10 = 60, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 7x-10 = 60 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & n

A rectangle is divided into four small rectangles, three of which are 24 square centimeter, 30 square centimeter and 32 square centimeter respectively Find the area of the shadow rectangle Make the formula simple