A rectangular iron block with a length of 10 cm, a width of 8 cm and a height of 7.85 cm is fused into a cylinder with a diameter of 8 cm at the bottom What is the height of this cylinder?

The area of the cylinder is: bottom area × height
Melting and casting, the area is equal to the cuboid, that is, 10 × 8 × 7.85 = 628 (cubic centimeter)
Let the height of the cylinder be x cm
（8/2）×（8/2）×3.14×X=628
X=6.25
Answer:

A cuboid iron block with a length of 10 cm, a width of 8 cm, a height of 5 cm and a cube iron block with an edge length of 5 cm are fused and cast into a cylinder. The diameter of the bottom surface of the cylinder is 30 cm. How many cm is the height?

10 × 8 × 5 + 5 × 5 × 5 = 525 (CC) 30 △ 2 = 15 (CM) 525 △ 3.14 × 152 = 525 △ 3.14 × 225 = 525 △ 706.5 ≈ 0.74 (CM). Answer: the height is 0.74 cm

Two rectangular iron blocks 8 cm long, 5 cm wide and 4 cm high are fused into a cylinder with a bottom area of 40 square cm. What is the height of the cylinder

H = (8 * 5 * 4 * 2) / 40 = 8 (CM)

The solution set of 15x & # 178; + 11x-12 ≤ 0

15x²+11x-12≤0
(3x+4)(5x-3)≤0
-4/3≤x≤3/5

Given that the symmetric point P2 (3-2a, 2a-5) of P1 about X axis is the integral point in the third quadrant (the point whose abscissa and ordinate are integers is called integral point), then the coordinate of P1 is______ ．

Given that P2 (3-2a, 2a-5) is the integral point in the third quadrant, then there is 3 − 2A ＜ 02A − 5 ＜ 0, and the solution is 1.5 ＜ a ＜ 2.5. Because a must be an integer, so a = 2, substituting it, we can get the coordinates of P1 (- 1, 1)

Let f (x) be an odd function with a period of 3 and f (- 1) = - 1, then f (2008)=______ ．

Because the period of the function is 3, so f (2008) = f (2007 + 1) = f (1) and because the function is odd, and f (- 1) = - 1, so f (1) = - f (- 1) = 1, so f (2008) = 1, so the answer is: 1

Why is an increasing function obtained by subtracting a decreasing function from an increasing function?
A simple example is given below

For example, f (x) = x is an increasing function,
Is g (x) = - x a decreasing function
F (x) - G (T) = x + x = 2x, which is still an increasing function
This can be specifically proved, but if you give me a simple example, I won't prove it. If you want me to prove it, ask me

Given that the linear equation L is 2x-5y + 10 = 0, and the intercept on the x-axis is a, the intercept on the y-axis is B, then | a + B | is equal to ()
A. 3B. 7C. 10D. 5

The linear equation L is 2x-5y + 10 = 0, and the intercept on the x-axis is a = - 5, and the intercept on the y-axis is b = 2, so | a + B | = | - 5 + 2 | = 3

3 math questions 100 points
(1) The speed of car a is 80% of that of car a. the speed of car a is ()% faster than that of car a
(2) The speed of the car is 80 km / h. The speed of the train is 80% faster than that of the car. How many kilometers does the train travel per hour? (write the formula)
(3) A. the two vehicles have been traveling from two places at the same time. Car a travels 50 kilometers per hour, which is equivalent to 125% of the speed of the vehicle. After 1.5 hours, how many kilometers have the two vehicles traveled? (write the formula)

25%
80+80*80%=144
1.5*（50+50/1.25）=135

The first group of inequalities in junior high school?

1.{5x-3>x-4 2.x-2(x-1)3
1+2/3-xx (3x-1)/40 5.2-5x

A rectangular iron block with a length of 10 cm, a width of 8 cm and a height of 7.85 cm is fused into a cylinder with a diameter of 8 cm at the bottom What is the height of this cylinder?