After adding 3cm to the two adjacent sides of a square, we get a new square. The area of the new square is 39 square centimeters larger than that of the original square. What's the area of the original square?

After adding 3cm to the two adjacent sides of a square, we get a new square. The area of the new square is 39 square centimeters larger than that of the original square. What's the area of the original square?

Let the side length of the original square be x cm. According to the meaning of the question, we can get: 3x + 3x + 3 × 3 = 39 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 6x + 9 = 39 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 6x = 30 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; X = 5 the area of the original square: 5 × 5 = 25 (square centimeter) a: the area of the original square is 25 square centimeter

After adding 3cm to the two adjacent sides of a square, we get a new square. The area of the new square is 39 square centimeters larger than that of the original square. What's the area of the original square?

Let the side length of the original square be x cm. According to the meaning of the title, we can get: 3x + 3x + 3 × 3 = 39 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 6x + 9 = 39 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 6x = 30 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; X = 5 the original square

1. When the length of a rectangle increases by 1cm and the width increases by 3cm, it becomes a square and the area increases by 33 square cm
Two cuboids with a length of 5 [DM], a width of 20 [cm], and a height of 10 [cm] are put together to form a large cuboid. The surface area of the cuboid can be reduced by () square centimeters at most, and by more than () square centimeters at least?
Find the rule: 4.9.19.39.79
2.3.5.8.( ).( ).34

When the length and width of a rectangle increase by 1cm and 3cm, it becomes a square, and the area increases by 33 square cm
Square side length (33 + 1 × 3) △ 1 + 3) = 36 △ 4 = 9cm
The original rectangular area is 9 × 9-33 = 81-33 = 48 square centimeters
Two cuboids 5 [DM] in length, 20 [cm] in width and 10 [cm] in height are put together to form a large cuboid. The surface area is reduced by (2000) square centimeters at most and (400) square centimeters at least
5 decimeters = 50 cm
50 × 20 × 2 = 2000 square centimeter
20 × 10 × 2 = 400 square centimeter
Regularity: 4.9.19.39.79. (159)
2.3.5.8.( 13).(21 ).34