It is known that the solution of the equation 1 / 2 [1-x] = 1 + K and 3 / 4 [X-1] - 5 / 2 [3x + 2] = 10 / 10 K-2 for X

It is known that the solution of the equation 1 / 2 [1-x] = 1 + K and 3 / 4 [X-1] - 5 / 2 [3x + 2] = 10 / 10 K-2 for X

What is 1 / 1x2 + 1 / 2x3 + 1 / 3x4 +. + 1 / 2003x2004

1/1x2+1/2x3+1/3x4+.+1/2003x2004
=1-1/2+1/2-1/3+1/3-1/4+.+1/2003-1/2004
=1-1/2004
=2003/2004

It's about inequality!
A sporting goods store predicted that a certain brand of sportswear would sell well, so it bought a batch of sportswear with 32000 yuan, which was sold out soon after listing. The store bought the second batch of sportswear with 68000 yuan, which was twice as much as the first batch, but the purchase price of each set was 10 yuan more
1) How many sets of this kind of sportswear did the mall buy in two times?
2) If the selling price of each suit is the same, and the total profit is no less than 20% after all the suits are sold out, how much is the selling price at least? (profit margin = profit △ cost × 100%)

In the first question, let the unknown number be the first, and then the equation can be worked out. If the first purchase quantity is x sets, then the second purchase quantity is 2x sets, and then the equation can be worked out: [(32000 / x) + 10] 2x = 68000, and then the equation can be worked out as x = 200, that is, if the first purchase quantity is 200 sets, the second purchase price is 400 sets, the first purchase price is 160 yuan, and the second purchase price is 170 yuan

If a commodity is sold at 80% of the marked price, it will get a profit of 960 yuan. If it is sold at 80% of the marked price, it will lose 832 yuan compared with the cost price. What is the cost price of this commodity?

(960 + 832) △ 1-80% = 1792 △ 20% = 8960 (yuan) 8960-960 = 8000 (yuan) a: the cost price of this commodity is 8000 yuan

Choose five different numbers from the nine numbers 1-9 to form a five digit number, which is required to be divisible by 3, 5, 7 and 11. What is the maximum number?

The maximum number is 98175

Two numbers are reciprocal to each other, and they must be in inverse proportion

If two numbers are reciprocal to each other, their product is 1
According to the definition of inverse proportion: because the product is certain, the two numbers must be in inverse proportion
There is a mistake on the second floor. These two numbers can be changed. They are functions

If point a (X-Y, x) and point B (x + 5, Y-8) are symmetric about the Y axis, find the coordinates of the point C (x, y) which is symmetric about the X axis, Y axis and origin
Junior one math problem, hope to see this problem will help the teacher, urgent!

So X-Y = - (x + 5) Y-8 = x, x = 3, y = 11, then the coordinates of C about X-axis symmetry are (3, - 11) about origin symmetry are (- 3, - 11)

99 * 38 * 38 how to use simple algorithm?

Your question should be: 99x38 + 38
99×38+38
=38×（99+1）
=38×100
=3800

Zhou Yi went with his father to climb Si Tian Mu mountain on Saturday. He found that the top layer of the forest in the West Tian Mu Mountain Nature Reserve is usually tall giant trees, under which are low shrubs, and under which are grass growing close to the ground. The main factor affecting the hierarchical distribution of these plants is ()
A sunlight B temperature c oxygen D moisture

a
Because of the different proportion of chlorophyll on the surface of plants, the higher the proportion of chlorophyll, the higher the absorption efficiency of plants to sunlight, so the stronger the adaptability to the environment. If trees grow in the shade, most of them can not survive, but weeds can

The base and area of a triangle are equal to those of a parallelogram. The height of a parallelogram is 10 cm. What is the height of a triangle?

20 cm