The Gauss sign [x] denotes the largest integer not exceeding the real number x, such as [- 1.23] = - 2, [1.23] = 1, then the solution set of the equation [log2 (lgx)]

The Gauss sign [x] denotes the largest integer not exceeding the real number x, such as [- 1.23] = - 2, [1.23] = 1, then the solution set of the equation [log2 (lgx)]

In order to make the formula meaningful, there is lgx 0. The minimum integer of lgx is 1, so x = 10
Let lgx = y, then log2lgx = log2y
Y = 2, so lgx = 2, that is, x = 100, and because X does not exceed 100, X is greater than or equal to 10 and less than 100

Simple calculation of 1.9 × 99 + 0.19

The answer to p36 in the first volume of ninth grade physics (Shanghai Science and Technology Press)?

Do it yourself

The original price of a commodity is 100 yuan. First raise the price by 110, then lower the price by 110. Is the current price more or less than the original price?

100 × (1 + 110) × (1-110) = 100 × 1110 × 910 = 110 × 910 = 99 (yuan) 100 ＞ 99 A: less than the original price

Why is the domain of definition of function y = root 2-x | 2x2-3x-2?

The number of square root is greater than or equal to 0
The denominator is not equal to 0
According to the meaning of the title
2-x>=0
2x²-3x-2≠0
It is necessary to solve this system of inequalities
x

A mathematical problem in the third grade of junior high school (quadratic equation with one variable)
For the quadratic equation AX & sup2; + BX + C = 0 (a ≠ 0), the following statement is given
① If C = 0, then the equation AX & sup2; + BX + C = 0 must have a root of 0
② If a and C are different signs, then the equation AX & sup2; + BX + C = 0 must have two unequal real roots
③ If A-B + C = 0, then the equation AX & sup2; + BX + C = 0 must have a root - 1
④ If the equation AX & sup2; + BX + C = 0 has two unequal real roots, then the equation AX & sup2; + BX + C = 0 must have two unequal real roots
The correct ones are: 1
Help to prove why it is right and why it is wrong
Wrong number 4
If the equation AX & sup2; + BX + C = 0 has two unequal real roots, then the equation BX & sup2; + BX + C = 0 must have two unequal real roots

The first one substitutes 0 into the equation, and the left and right sides are equal
Second, because △ = B ^ 2-4ac, if a C is different, then B ^ 2-4ac must be greater than zero, so there must be two unequal real roots
The fourth question seems not big, right? The two equations are the same
Change the question hi me

The price of a TV set increases by 10% at first and then decreases by 10%

The price of a TV set increases by 10% at first and then decreases by 10%. Compared with the original price before the price increase, the current price decreases by 1%, which is 99% of the original price

The x power of 2000x-1.05 + 1500 = 0 to find x

solve('2000*x-1.05^x+1500=0')
ans =
-.74951795426550889290223551408253
270.63754640238090569623474021880

Give examples to illustrate the meaning of the following algebraic expressions
(1) One in two can be interpreted as
(2) (a + b) (a-b) can be interpreted as
(3) The a-cube of 8 can be interpreted as
(4) 5 of M can be interpreted as

(1) 1 / 2 x can be interpreted as: 1 / 2 of the park ticket, how much does it cost for X people to go to the park?
(2) A + b) (a-b) can be interpreted as: the length of the rectangle is (a + b), the width is (a-b), and the area of the rectangle is calculated
(3) 8a3 can be interpreted as: what is the volume of eight small cubes with side length a
(4) 5 of M can be interpreted as: 5 pairs of gloves m yuan, each pair of gloves 5 of M yuan

If a commodity is sold at 80% of the price, the profit will be 960 yuan. If it is sold at 80% of the price, the loss will be 832 yuan?
（960×80%+832）÷（1-80%）

Guo Dunyong: how to understand the problem-solving process: (960 × 80% + 832) / (1-80%)? If a commodity is sold according to the price, the profit will be 960 yuan. If it is sold according to 80% of the price, the loss will be 832 yuan