Ask for two sixth grade math problems, 100,000 urgent

1. 2n+1

2.Other things can be done within 15 minutes of boiling water, and it takes a total of 15 minutes.

Do you boil water in a kettle? That's 16 minutes.

Use three for the first triangle, and only add two for each later.

n triangles need:

3+2(n-1)=3+2n-2=2n+1.

Swing 8 triangles in a row, you need:

2 8 + 1 = 17 roots.

Co-ordination method. It takes 1 minute to wash the kettle, then boil the water for 15 minutes.

A total of 1+15=16 minutes.

While boiling water, you can do:

Wash the teapot for 1 minute, wash the teacup for 1 minute, and leave the tea leaves for 2 minutes.

It takes 1+1+2=4 minutes < 16 minutes.

That is, while boiling water, other work can be done.

It takes a minimum of 16 minutes.

1,2 8+1=17 (root).

Answer: 2n+1 matches are used for n triangles, and 17 matches are used for 8 triangles.

2. Answer: Wash the kettle first, then boil the water, and wash the teapot and put the tea leaves in the teapot during the boiling water, for a total of 16 minutes. Satisfied.

Root. 2.Wash the kettle for 1 minute, boil the water for 15 minutes, wash the teapot for 1 minute, wash the teacup for 1 minute, and put the tea leaves for 2 minutes, that is, a total of 16 minutes.

1. Solution: 3+2*(n-1).

2. Wash the kettle for 1 minute, boil the water for 15 minutes (wash the teapot for 1 minute, wash the teacup for 1 minute, and put the tea leaves for 2 minutes in the process of boiling water). 16 minutes in total.

1.This problem is a series of equal differences, and the general formula for the equal difference series is an=a1+(n-1)d

A1 is the first item.

d is the tolerance. n is the number of items.

The a1 of this question is 3 and the tolerance is 2

So an=3+(n-1)2

Simplify to an=2n+1

The final answer is to place n triangles with 2n+1 matches.

First wash the kettle for 1 minute, boil the water for 15 minutes, wash the teapot for 1 minute when boiling water, wash the teacup for 1 minute, and finally put the tea leaves for 2 minutes.

18 minutes in total!

If you can drink it with tea leaves, you can put tea leaves when boiling water, so it takes 16 minutes) The first question is about the knowledge of the first year of high school, which is just theoretical knowledge, it is a model, it doesn't matter if you don't understand it, you should be able to understand it!! I just finished the exam

Hope you can help!!

2n+1 first boil water, wash various utensils at the same time (15 minutes in total), and finally make tea.

Question 1. Swing n triangles with 2n plus 1 match.

This pendulum is equivalent to adding two matches by adding one triangle.

Question 2.

The first question is to place n triangles with 2n+1 matches.

The second question, wash the kettle first, then boil the water, and wash the teapot and teacup during the boiling water, and put the tea leaves in the teacup, for a total of 16 minutes

to the nth power.

2.Wash the kettle, boil the water for 15 minutes, wash the teapot at the same time, wash the teacup, and put the tea leaves.

1. The cylinder of equal bottom and equal height is 3 times the volume of the cone.

2. Some scholars have done experiments on a cylinder and a cone, which are the same height as the bottom, and the cone, are filled with sand and poured into the cylinder, and the height of the sand is 1 3 of the height of the entire cylinder, so there is the volume of the cone.

3. It is to calculate the volume of the cylinder of equal height at the bottom and equal height in multiplied by 1 3v cone = 1 3 r h is pi r is the radius h is high I hope to solve your problem, and hope to adopt...

The formula for the volume of the round vertebrae: 1 3s (bottom) * h while the formula for the volume of the cylinder is: s (bottom) * h Comparing the two, there is only a difference of 1 3, that is, the volume of the round vertebra is 1 3 of the cylinder

1. Derivation of the formula for calculating the volume of a cylinder:

Cut the cylinder and put it together into an approximate cuboid, so that the volume of the cylinder is converted into the volume of the cuboid. According to the volume of the cuboid with the base area high, the volume of the cylinder with the base area is high.

Represented by letters: v sh

2. The derivation of the formula for calculating the volume of the cone is obtained by experiment

Fill a cone with sand and pour this sand into a cylinder of equal height to the bottom of the cone, and these sand are exactly 3 1 of the cylinder, so the volume formula of the cone is v base area multiplied by height and then multiplied by 3 1.

The relationship between a cylinder of equal height and a conical body is proved experimentally: the volume of a cone is one-third of the volume of a cylinder of equal height to it.

Indicated by letters:

v=1/3sh

1.The volume of the round vertebral is one-third that of the cylinder.

2.You can fill a hollow circle with water and pour it into a cylinder of the same height as the bottom, and pour it exactly three times.

Round vertebrae = 1 3x height x (pai) x radius squared.

1.The cone is equal to 1 3 of the cylinder

2.Load the sand into cylinders and cones, and draw conclusions.

Piece. 2. It has become smaller, because for the parallelogram, the length of the bottom edge has not changed, but after the deformation, the height of the coarse Qing has become smaller, so the area of the bottom of the object has also become smaller. If you keep pulling it, it will eventually be pulled into a straight line of stools, and the area will be 0

Inner tube radius: 2 2 = 1 cm.

Inner tube cross-sectional area: square centimeters.

Volume of water flowing out per second: cubic centimeters = liters.

5 Minute Flow: L.

Water pipe cross-sectional area s = *(2 2) = cm

The volume of water that flows out for five minutes.

v = cross-sectional area x flow velocity x time.

3000 cubic centimeters.

3 cubic decimeters.

3 liters.

5 minutes = 5 * 60 seconds = 300 seconds;

cross-sectional area of the water pipe = square) = square centimeter (radius is 2 2 = 1);

Volume of water: cubic centimeters = cubic decimeters (liters).

5 minutes = 5 * 60 = 300 seconds.

The outflow of water is to find the volume.

Square * 10 * 300 = 9420 square centimeters = 9420 ml = liters * is the multiplication sign.