The length of a rectangular lawn is 25 meters and the area is 450 square meters. If it grows to 75 meters and the width remains unchanged, what is the area of the expanded lawn?

The length of a rectangular lawn is 25 meters and the area is 450 square meters. If it grows to 75 meters and the width remains unchanged, what is the area of the expanded lawn?

Width = 450 / 25 = 18m
Current area = 18x75 = 1350 square meters

There is a lawn in the park, which is 8 meters wide and covers an area of 480 square meters. In order to meet the needs, we need to increase the width to 60 meters and keep the length unchanged. How many square meters more than the original lawn area after expansion?

480 / 8x60-480 = 3600-480 = 3120 square meters

A rectangular lawn in the school garden is 480 square meters. If the length remains unchanged and the width is increased by 6 meters, what is the area of the expanded lawn
A rectangular lawn in the school garden is 480 square meters. If the length remains unchanged and the width is increased by 6 meters, what is the lawn area after expansion

If the length is a meter and the width is B meter, then AB = 480,
The expanded lawn area is a × (B + 6) = 480 + 6A (M2)

25x−13y+1＝02x+2y＝7

From the meaning of 25X − 13y = − 1, ① 2x + 2Y = 7, ②, ① × 6 + ②, 125x + 2x = - 6 + 7, the solution is x = 522. Substituting the value of X into equation ①, the solution is x = 522y = 3611

When a ball falls from a height, it bounces 4.8 meters for the first time, 2.4 meters for the second time and 1.2 meters for the third time. According to this rule, how many meters does the ball bounce for the fourth time? How many meters did the ball fall from?

1.2 △ 2 = 0.6 (m), 4.8 × 2 = 9.6 (m), a: the ball bounced up 0.6 m for the fourth time; the ball fell from the height of 9.6 m at the beginning

When x is a value, the value of the algebraic formula 2X-4 / x ^ 2-4x + 4 is an integer
Simplify 1 / √ 2-1 = 2-1 / √ 2-1 = (√ 2 + 1) (√ 2-1) = √ 2 + 1, please answer the following questions according to the method provided
When x is an integer, the value of the algebraic formula 2X-4 / x ^ 2-4x + 4 is an integer

The original formula = 2 (X-2) / (X-2) & # = 2 / (X-2) is an integer
Then X-2 is a divisor of 2
So X-2 = ± 1, ± 2
So x = 1, x = 3, x = 0, x = 4

Calculate a ^ 2-5A + 6 / A ^ 2-16 times a ^ 2 + 5A + 4 / A ^ 2-4 divided by A-3 / A + 4

A ^ 2-5A + 6 / A ^ 2-16 times a ^ 2 + 5A + 4 / A ^ 2-4 divided by A-3 / A + 4 = [(A-2) (A-3) / (a + 4) (A-4)] × [(a + 1) (a + 4) / (a + 2) (A-2)] × [(a + 4) / (A-3)] = (a + 1) (a + 4) / (a + 2) (A-4) = (A & # 178; + 5A + 4) / (A & # 178; - 2a-8)

The area of a triangle farm is 5.6 square meters, the bottom is 2.8 meters, and the height is ()?

5.6×2÷2.8
=11.2÷2.8
=4 (m)

It is known that the solution of the equation KX = 4-x about X is a positive integer

The original equation is transformed into KX + x = 4, that is, (K + 1) x = 4, the solution of the equation KX = 4-x about X is a positive integer, and the product of K + 1 and X is 4, then K + 1 = 4 or K + 1 = 2 or K + 1 = 1 can be obtained, and the solution is k = 3 or K = 1 or K = 0. Therefore, the integer solution of K can be obtained as 0, 1, 3

A semicircular flowerbed, with an area of 56.52 square meters, how about the perimeter
The area of a triangle is 3 / 4 square meters, its bottom is 1 / 3 meters long and () meters high.

Radius x radius = 56.52x2 / (3.14) = 36
Radius = root 36 = 6
Perimeter = 2x3.14x6
=30.84m