Question 2 (2) on page 21 of class assignment book of Mathematics Grade 6 Volume 1 In winter, Shen Ming runs 2000 meters a day, one ninth more than Li Hua. How many meters does Li Hua run every day?

Question 2 (2) on page 21 of class assignment book of Mathematics Grade 6 Volume 1 In winter, Shen Ming runs 2000 meters a day, one ninth more than Li Hua. How many meters does Li Hua run every day?

2000 divided by (1 + 1 / 9)
=2000 times nine tenths = 1800 meters

A rectangular pool, 20 meters long, 15 meters wide and 2 meters deep. Cement the four walls and bottom of the pool, and calculate the area of cement

　　﹙20＋15﹚×2×2＋20×15=440﹙m²﹚
The area of plastering cement is 440m

The quotient of a divided by B is 0.35. The simplest integer ratio of a and B is______ ．

Because the number of a / b = 0.35, so the number of B is 1, then the number of a is 0.35, the number of a: B = 0.35:1 = (0.35 × 100): (1 × 100) = 35:100 = 7:20; so the answer is: 7:20

The volume of a cylinder is 18 cubic meters, the height is 0.9 decimeters, and the bottom area is how many square decimeters?

18 / 0.9 = 20 decimeters

5 / 7 of a number is 15 less than the quotient of 45 divided by 9 / 7

Let this number be X
Then 5x / 7 = 45 △ 9 / 7-15
5x/7=35-15=20
x=20÷5/7=28
A: the number is 28

The circumference of the bottom surface of a cube fuel tank is 12 decimeters. How many square decimeters does the fuel tank cover? How many square decimeters does it take to make the fuel tank?

First find the side length: 12 △ 4 = 3
Floor area: 3 × 3 = 9 square decimeters
Sheet iron: (stamped)
3 × 3 × 6 = 54 square decimeters
(no cover)
3 × 3 × 5 = 45 square decimeters

1 + 1 / 1 + 2 + 1 / 1 + 2 + 3 + 1 / 1 + 2 + 3 + 4 +. + 1 / 1 + 2 + 3 +

1+1/1+2+1/1+2+3+1/1+2+3+4+.1/1+2+3+.+1000
=1+1/[(1+2)×2÷2]+1/[(1+3)×3÷2]+1/[(1+4)×4÷2]+.1/[(1+1000)×1000÷2]
=1+2/(1+2)×2+2/(1+3)×3+2/(1+4)×4+.2/(1+1000)×1000
=1+2×(1/2-1/3+1/3-1/4+1/4-1/5+.+1/1000-1/1001)
=1+2×1/1001
=1 and 2 / 1001

In RT △ ABC, the bisector of acute angle a intersects with the bisector of the adjacent complementary angle of acute angle B at point D, then ∠ ADB=______ Degree

If the size of acute angle ∠ A is x, then the adjacent complementary angle of acute angle ∠ ABC is 90 ° + X; then ∠ ADB = 180 ° - (x2 + 90 ° - x + 45 ° + x2) = 45 °

A simple formula (a, B real numbers) that can be combined by asinx + bcosx

Asinx + bcosx = under root sign (a ^ 2 + B ^ 2) sin (x + C)
Where Tanc = B / A

The area of trapezoid ABCD is 45 square centimeter, the area of triangle doc is 5 square centimeter, the area of triangle AOB is calculated
Point O is in the trapezoid

Where is point o? Inside or outside?
Work out the CD first
(AB+CD)*6/2=45
CD=5
Distance from point O to CD = 5 (area) * 2 / 5 (CD) = 2
The area of O above CD is ab * (6 + 2) / 2 = 40
The area of O under Cd is ab * (6-2) / 2 = 20