The plan of a playground is 4cm long and 2cm wide. The 1cm in the plan is equal to the actual 25m. How many square meters is the actual surface of the playground? Using the proportion equation to solve the problem

The plan of a playground is 4cm long and 2cm wide. The 1cm in the plan is equal to the actual 25m. How many square meters is the actual surface of the playground? Using the proportion equation to solve the problem

(25×4）×（25×2）
=100×50
=5000 square meters

How many meters is 25 meters and 7 centimeters

25.07m

Find the value of X in the following format, where the square of 1 16x (without brackets) minus 49 = 0, and the square of 2 (x-1) equals 25

1) 16x ^ 2-49 = 0 = = > x ^ 2 = 49 / 16 = = > x = + / - 7 / 4 2) (x-1) ^ 2 = 25 = = > X-1 = + / - 5 = = > x = 6 or - 4

To solve the equation, the square of 81x minus 16 = 0 is solved by the quadratic solution of one

81x²-16=0
81x²=16
x²=16/81
x=±4/9

Arrange the natural numbers according to the following table. What are the numbers in row 16, column 13 and row 12, column 25? What are the rows and columns of 149? 2013?
1 2 9 10 25 26
4 3 8 11 24 ……
5 6 7 12 23 ……
16 15 14 13 22 ……
17 18 19 20 21 ……

When I = J, a (I, J) is the average of the number of rows and columns (only including the part in front of a (I, J)), and the number of the previous column is equal to a (I, J) - 2, and the number of the upper row is equal to a (I, J) + 2. When I = J, that is, all the points in the lower right corner of the square in the graph, they are regular: 1, 3, 7, 13, 21

To explore the relationship between the current on the resistance and the voltage at both ends, to measure the resistance of the small bulb, to measure the electric power of the small bulb and so on
One experiment at a time

Sliding rheostat has a common function in every experiment: protection circuit
Specific to different experiments also have different effects
In exploring the relationship between the current on the resistance and the voltage at both ends, we need to add different voltages to the resistance, so the function of sliding rheostat is to change the voltage at both ends of the constant resistance
In the experiment of measuring the electric power of small bulb, it is required to measure the electric power under three conditions of rated voltage, greater than rated voltage and less than rated voltage, so the function of sliding rheostat is to change the voltage at both ends of bulb
In the experiment of measuring the resistance of small light bulb, the resistance of small light bulb is generally not measured, but the resistance of constant value resistance is generally measured. In order to make the result error small, the method of average value by multiple measurements is commonly used to reduce the error. Therefore, the function of sliding rheostat is to change the voltage at both ends of the resistance and the current passing through to make multiple measurements, so as to reduce the error
Because the resistance of small bulb changes greatly with temperature, the resistance of small bulb cannot be averaged

1:2-1:4-1:8-1:16-1:64=
emergency

1/2-1/4-1/8-1/16-1/64
=32/64-16/64-8/64-4/64-1/64
=3/64
Should the title be:
1/2-1/4-1/8-1/16-1/32-1/64
=32/64-16/64-8/64-4/64-2/64-1/64
=1/64

When a voltage of 2V is applied at both ends of a section of conductor, the current intensity passing through it is 0.4A, and the resistance of this section of conductor is Ω; if the voltage at both ends of it is 4V,
What is the current through it____ A. What is the resistance of this section of conductor___ Ohm, if there is no voltage at both ends of it, the current through it is___ What is the resistance of this section of conductor____ If the current intensity through it is 0.6A, the resistance of this section of conductor is___ The voltage at both ends is___ V

When a voltage of 2V is applied at both ends of a section of conductor, the current intensity passing through it is 0.4A, and the resistance of this section of conductor is 5 Ω; if the voltage at both ends of it is 4V, the current intensity passing through it is 0.4A__ 0.8__ A. What is the resistance of this section of conductor_ 5__ Ohm, if there is no voltage at both ends of it, the current through it is_ 0A__ What is the resistance of this section of conductor__ 5 Ω__ If the current intensity through it is 0.6A, the resistance of this section of conductor is_ 5 Ω__ The voltage at both ends is_ 3__ V

The solution set of the equation x & # 178; - 9 = 0 is?

{x ^ 2-9 = 0} = {3, - 3}

How many K ohms is 1m ohm

1m ohm = 1000K ohm