On the way of spring outing, students sometimes walk and sometimes sing

On the way of spring outing, students sometimes walk and sometimes sing

On the way of spring outing, the students sang while walking

The students are singing happily to the park!

The students sang happily and went to the park

Paint unit is square, how to convert into kilogram
Coatings for decorative materials

First of all, the paint unit is square. I think what we should say is how many square meters can be painted per kilogram of paint. We should also know how many square meters we can paint in total. Then the total number of square meters we can paint divided by the number of square meters we can paint per kilogram of paint will become kilogram

Multiplicative allocation

（A+B)×C=A×C+B×C

F (2x-1) = 4x-2 to find f (x)

f(2x-1)=4x-2
Let 2x-1 = t
Then 2x = t + 1
x=(t+1)/2
f(2x-1)=f(t)=4*(t+1)/2-2=2t+2-2=2t
So f (x) = 2x

How to compare the amount of heat released by the two reactions, such as the complete combustion of solid s and gas s; the reaction of hydrogen and oxygen to produce liquid water and gaseous water, etc
Specific judgment methods

Take "solid s and gas s complete combustion" as an example. Solid s becomes gaseous s with the same amount of energy, and their state after combustion is the same. Therefore, gas will emit more energy, and the extra energy is the amount of energy required for solid to become gas

Given x ^ a = 5, x ^ B = 3, find the value of x ^ (3a-2b)

x^a=5
(x^a)^3=x^(3a)=5^3=125
x^b=3
(x^b)^2=x^(2b)=3^2=9
x^(3a-2b)
=x^(3a)/x^(2b)
=125/9

Volume and volume
Requirements: formula or sum formula. Also answer and unit name
1. A cuboid is made up of 1980 cuboids whose edges are 1cm long. The cuboid is 11cm high and grows wider than the cuboid. What is the height and width of the cuboid?
2. Put a rectangular iron block in a water basin 120 cm long and 60 cm wide. In this way, the water surface will rise by 2 cm. The known length and width of the iron block are 20 cm, so the height of the iron block can be calculated
3. A 32 cm long rectangular iron sheet, four corners of each side of the 4 cm long square iron sheet, and then make an open iron box, the volume of this iron box is 1920 cubic cm. What is the area of this iron sheet?
On the first floor, if you can't, don't send it

1. Calculate the total volume
1980 * (1 * 1 * 1) = 1980 CC
First decompose the prime factor. 1980 = 2 * 2 * 3 * 3 * 5 * 11
According to the fact that the length is larger than the width and the width is larger than the height, it can be calculated that the length is 3 * 5 = 15cm and the width is 2 * 2 * 3 = 12cm
2. Calculate the cuboid volume according to the water surface rising 2 cm
120 * 60 * 2 = 14400 cm3
Then find the height of the iron block. 14400 / 20 / 20 = 36cm
3. Find the width of the rectangle first
1920 / 4 / 32 = 15 cm 15 + 4 * 2 = 23 cm
Find the area of the sheet again
23 * 32 = 736 square centimeter

The fifth power of 1.53 × 10 km = () = () mm
76 × 10, NM = () = () M

1.53x10^5 km = 1.53x 10^8 m =1.53x 10^11mm
4.76x10^4nm = 4.76x 10^-2mm=4.76x10^-5 m

What is the 49th digit after PI decimal point?

3.1415926535 8979323846 2643383279 5028841971 6939937510 5820974944 5923078164 0628620899 8628034825 3421170679 :1008214808651 3282306647 0938446095 5058223172 5359408128 4811174502 8410270193 8521105...