Calculation of 4300 * 25 + 43 * 7500 with simple method Calculation of 4300 * 25 + 43 * 7500 with simple method

Calculation of 4300 * 25 + 43 * 7500 with simple method Calculation of 4300 * 25 + 43 * 7500 with simple method

4300×25+43×7500 =43×100×25+43×100×75
=43×100×（25+75）
=43×100×100
=430000

Among the following approximations, the one with 3 significant numbers is ()
A. 5430b. 5.430 × 105C. 5430d. 54300

The significant number of the number a × 10N expressed by scientific notation is only related to a and has nothing to do with 10N. The significant number of the approximate number 54300 is only related to 54300 and has nothing to do with 10000. There are five, four and three significant numbers

19 / 23-19 / 23 * 1 / 24

19/23-19/23*1/24
=(19/23)*(1-1/24)
=(19/23)*(23/24)
=19/24

In order to deal with the international financial crisis, Jinlianhua supermarket has the following plans when dealing with a certain commodity: ① increase the price by 20%, and then reduce the price by 20%; ② reduce the price by 20%, and then increase the price by 20%; ③ increase the price by 15%, and then reduce the price by 15%? What kind of price adjustment scheme do you suggest the supermarket should adopt?

Suppose the original price of this commodity is a yuan, then ① (1 + 20%) (1-20%) a = 0,96a; ② (1-20%) (1 + 20%) a = 0,96a; ③ (1 + 15%) (1-15%) a = 0,9775a; therefore, the price adjustment result does not restore the original price. Because 0,9775a > 0,96a, it is suggested that supermarkets should adopt the third price adjustment method

If the domain of definition and value of function y = 12x2 − x + 32 are [1, b], then the value of real number B is ()
A. 2B. 3C. 4D. 5

The number y = 12x2 − x + 32 = 12 (x2 − 2x) + 32 = 12 (x − 1) 2 + 1, the symmetry axis of the parabola is x = 1, because the domain of definition is [1, b], so the function increases monotonically on [1, b], because the domain of definition and the range of value are [1, b], so 12 (B − 1) 2 + 1 = B, the solution is b = 3 or B = 1 (rounding)

Solve the equation, fast
In a circle, there is a square in the lower right corner. The radius of the circle is the side length of the square. The area of the square is 80 square meters. How many square meters is the area of the circle?

80π
If the area of a square is 80, the side length of the square is root 80, so the radius of the circle is root 80, so the area of the circle is 80 π

After the first 5% price reduction of a product, no one wanted to buy it, so the store had to cut the price by another 5% for promotion. What's the price now
Use fractional multiplication instead of equations

4/5 * 4/5 = 16/25
The result was 16 out of 25

Given that the product of n natural numbers is 2010, and the sum of these n natural numbers is also 2010, what is the maximum value of N

Known: 2010 = 1 * 1 1*2*3*5*67,2010=1+1… 1 + 2 + 3 + 5 + 67, so n = (2010-2-3-5-67) + 4 = 1933 + 4 = 1927

Mathematics problem
A certain plant is suitable to grow in the mountain area with the temperature of 18 ~ 20 ℃ (including 18 and 20 ℃). It is known that the temperature drops by 0.55 ℃ every 100 meters above sea level. Now the temperature at the foot of the mountain is 22 ℃. If the foot of the mountain and the sea level are at the same level, it is more suitable to plant in the mountain area with the altitude of X meters_________________________________________
(please explain the process and reason of listing inequality, otherwise no score will be given.)

18≦22-0.55x/100≦20
The measured temperature at the foot of the mountain is 22 degrees. It is known that the temperature drops by 0.55 degrees for every 100 meters above sea level,
The plant is planted in the mountain area with an altitude of X meters
Reduced temperature 0.55x/100
Actual temperature 22-0.55x/100
This kind of plant is suitable to grow at the temperature of 18 ~ 20 ℃ and has a good growth potential
18≦22-0.55x/100≦20
X is 363.36 ~ 727.27m

What does 12 divided by 0.25 mean

There are several 0.25 in 12