Simple operation of 27 × 44 + 27 × 55 + 27

Simple operation of 27 × 44 + 27 × 55 + 27

27×44+27×55+27
=27×(44+55+1)
=27×100
=2700

273-73-27 how to calculate with simple formula?

=273-(73+27)
=273-100
=173

A simple algorithm of 273 minus 73 minus 27

273-(73+27)=273-100=173

The area of a rectangle and a square is 1225cm2, and that of a circle is 1256cm2? Which is the smallest? If the areas of these three figures are equal, can you find the size relationship between their girths?

The area of a rectangle and a square is 1225cm2, and that of a circle is 1256cm2. The maximum perimeter of the three figures is rectangle, and the minimum is circle. When the area of the three figures is equal, the relationship of their perimeter is reversed, that is, rectangle > square > circle

If the rational numbers a and B satisfy the quadratic power of | ab-2 | + (1-B) = 0, try to find the value of 1 / AB + 1 / (a + a) (B + 1) + 1 (a + 2) (B + 2) +... + 1 / (a + 2004) (B + 2004)
"/" is the fractional line
Not 1 / AB + 1 / (a + a) (B + 1) + 1 (a + 2) (B + 2) +... + 1 / (a + 2004) (B + 2004)
It's 1 / AB + 1 / (a + 1) (B + 1) + 1 (a + 2) (B + 2) +... + 1 / (a + 2004) (B + 2004)

The absolute value and the square are greater than or equal to 0
If the first holiday is 0, it is equal to 0
So ab-2 = 0, 1-B = 0
b=1,a=2/b=2
So the original formula = 1 / 1 * 2 + 1 / 2 * 3 + 1 / 3 * 4 + +1/2005*2006
=1-1/2+1/2-1/3+1/3-1/4+…… +1/2005-1/2006
=1-1/2006
=2005/2006

The calculation of factorization in the second year of junior high school should be a little more difficult
We can use the square difference formula and complete square

The square of 9x-24xy + the square of 16y

If the area between the two squares is 12 square meters, the distance between them is 1 cm
What's the area of a square in centimeters

As shown in the figure below, the area of the colored part is 12 / 4 = 3, and the area of the green part is 1 / 2, so the area of the red part is 3-2 * 1 / 2 = 2. At the same time, the width of the red rectangle is 1, and its length is 2, which is the side length of the small square. Then the side length of the large square is the side length of the small square plus 2, which is 4

How do scientists measure the distance between the earth and the sun?

Triangulation (also known as parallax method). The earth orbits around the sun with a diameter of about 300 million kilometers. Astronomers can observe a star one day, and observe the same star after half a year. They can find the difference of viewing angles between the two stars. Using a very simple trigonometry principle, they can observe the stars from different perspectives, This method is suitable for measuring stars within 400 light years from the earth
For Stars 400 light years away from the earth, there is no direct measurement method at present, so astronomers use the brightness measurement method instead, which is based on Doppler effect
Measuring the distance between the earth and the sun is very simple. There are several methods to measure the distance between the sun and the earth. One is to use the transit of Venus (that is, the sun and Venus are just in a straight line with the earth), that is, to send a beam of radar wave from the earth, hit Venus, and then reflect it back from Venus. The other is to use asteroids to measure the distance between the sun and the earth

As shown in the picture, a and B measure the distance from the river bank to the cliff. Standing on the bank, a is 20m away from B. they stand on a straight line from the river bank to the cliff. A fires a shot, B hears two shots, and the interval between the two shots is 4S. Calculate the distance from the river bank to the cliff. (set the sound propagation speed as 340 & nbsp; m / s)

Suppose that the distance between the river bank and the cliff is s, the time taken by B to hear the gunshot for the first time after a shot is T1 = s a b v, and the time taken by B to hear the gunshot for the second time after a shot is T2 = s a B + 2sv. According to the title t2-t1 = t, that is: s a B + 2sv-s a b v = t, we can get the distance from the river bank to the cliff: S = vt2 = 340m / s × 4s2 = 680m A: the distance from the river bank to the cliff is 680m

1. The area of a square is 8x square, and its circumference is______ .
2. Root sign x + under root sign - x (find out the meaning of X in what range)

1. If the area of a square is 8x, then the side length is (2 √ 2) X,
Its circumference is (8 √ 2) X
2. Root sign x + under root sign - x (find out the meaning of X in what range)
X ≥ 0, - x ≥ 0
The solution is x = 0
When x = 0, it is meaningful