A shopping mall sells desk lamps with a purchase price of 30 yuan at 40 yuan, with an average of 600 lamps sold per month. The survey shows that every 1 yuan increase in the price of this kind of desk lamp will reduce its sales by 10. In order to achieve an average monthly sales profit of 10000 yuan, the shopping mall decides to take price control measures to expand sales and reduce inventory. How much yuan should the price of this kind of desk lamp be? How many table lamps should I enter at this time?

Let the selling price be x yuan. According to the equation (X-30) [600 - (x-40) × 10] = 10000, we can get x 1 = 50, x 2 = 80. In order to expand sales volume and reduce inventory, x 2 = 80 should be discarded. When x = 50, [600 - (x-40) × 10] = 500. A: when the selling price is 50 yuan, we can get 500

Factorization factor x4-9 in real range=______ ．

x4-9=（x2）2-32=（x2+3）（x2-3）=（x2+3）（x+3）（x-3）．

If real numbers x and y satisfy y = radical 2-x + radical X-2 + 1, find the value of x ^ 2-y ^ 2008

Y = radical 2-x + radical X-2 + 1,
X=2,Y=1
X^2-Y^2008=4-1=3

If the line ax + y + 2 = 0 has a common point with the line segment connecting a (- 2,3) and B (3,2), then the value range of real number a is______ ．

Draw a figure, as shown in the figure; combined with the figure, we know that: the straight line ax + y + 2 = 0 can be changed into y = - AX-2, ∵ the straight line passes through a (- 2,3), ∵ 2A + 3 + 2 = 0, and the solution is a = 52; the straight line passes through B (3,2), ∵ 3A + 2 + 2 = 0, and the solution is a = - 43; ∵ the value range of a is a ≤ - 43, or a ≥ 52

Let a > 0, b > 0, then ln (AX) / ln (BX) tends to infinity limit in X

The result is 1

Given the function f (x) = ㏒ a (x power of a - x power of B) (a, B are constants), when a, b > 0 and a ≠ B, the domain of definition of function f (x) is obtained

To make a function meaningful, a ^ X - B ^ x > 0,
That is a ^ x > b ^ X
(a/b)^x >1,(a/b)^x > (a/b)^0
(1) When a > b > 0, a / b > 1, then x > 0, that is, the domain of F (x) is (0, + ∞);
(2) When b > a > 0, 0

Pick up a friend at the airport

go to the airport to meet friends

What is 50 + 20

Let a = 3x & sup2; + 5Y & sup2; - 2XY & sup2; b = 4x & sup2; - 2Y & sup2; + XY & sup2; find 3b-a

3B-A
=3(4X²－2Y²﹢XY²)-(3X²﹢5Y²﹣2XY²)
=12X²-6Y²+3XY²-3X²-5Y²+2XY²
=9X²-11Y²+5XY²

English words from January to December

January,February,March,April,May,June,July,August,September,October,November,December.