Put the proper prime number in the brackets below 10=（ ）+（ ）=（ ) +( ) 10=( )+ ( )+( )=（ ）×（ ） 20=( )+( )=( )+( ) 20=( )+( )+（ ）=（ ）×( )×（ ）

Put the proper prime number in the brackets below 10=（ ）+（ ）=（ ) +( ) 10=( )+ ( )+( )=（ ）×（ ） 20=( )+( )=( )+( ) 20=( )+( )+（ ）=（ ）×( )×（ ）

10=（ 3）+（ 7 ）=（ 1 ) +( 9 )
10=( 1)+ ( 2 )+( 7 )=（ 2 ）×（ 5 ）
20=( 17 )+( 3 )=( 9 )+( 11 )
20=( 13 )+( 3 )+（ 4 ）=（ 1 ）×( 4 )×（ 5 ）
In other words Repeatable, right?

32 = + = + = + prime in brackets

32=3+29=13+19
27 is not a prime number, and I gave it all

Circle x square + y square-4x-6y + 8 = 0, any point on the circle (x, y), find the maximum value of y than x

Let Y / x = n, then there is y = NX, the equation brought into the circle is, (1 + n ^ 2) x ^ 2 - (4 + 6N) x + 8 = 0, if the equation has a solution, then there is △ > = 0, there is (4 + 6N) ^ 2-32 (1 + n ^ 2) > = 0, if the simplification has n ^ 2 + 12n-4 > = 0, then the solution is n = - 6 + 2 √ 10, by the way, y has no maximum value than x, the maximum is infinite, and the minimum is infinite

Any number will do. There must be an answer

1) 2 / 3-2 / 5 + 2 / 4 23 / 30 = 40 / 60-24 / 60 + 30 / 60 = 16 / 60 + 30 / 60 = 46 / 60 = 23 / 30 (3) 3 / 2 + 4 / 5-7 / 6 = 45 / 30 + 24 / 30-35 / 30 = 69 / 30-35 / 30 = 34 / 30 = 17 / 15 = 1 2 / 15

If the central angle of a sector is reduced by two times and the radius is increased by two times, its area will be reduced

Sector area = π NR ^ 2 / 360 (n is the degree of center angle, R is radius)
Therefore, if the central angle of a circle is reduced by two times and the radius is expanded by two times, its area will be expanded by two times

How to find the maximum vibration velocity and acceleration of each particle in harmonic motion? By vibration equation or by wave equation

The general equation of vibration is y = Hsin (Wx + a) + B
If we take the derivative of velocity, we take the second derivative of acceleration,

Cut a piece of red paper 120 cm in length and 80 cm in width into a square of the same size and as large as possible, and there is no surplus. At least how many pieces can be cut?

At least six
Because the greatest common divisor of 120 and 80 is 40
So the side length of a square is 40
120×80÷40²=6

On the displacement problem of the uniform velocity linear motion in physics ～
In the uniform velocity linear motion, the area between the VT image and the x-axis is the particle displacement. Why is this?

Not only is the area of VT image equal to the distance in this period, all VT images are like this
Strict proof should be applied to the integral of Advanced Mathematics (there is a course in the University, the name of the textbook is also this, we are freshmen)
You can also understand that the area in VT image is x * y (if it is not a rectangle, please divide it into n rectangles plus a very small irregular shape. At this time, only the sum of rectangles is calculated. When the N rectangles become larger and larger, the error becomes smaller and smaller. When it is infinite, this value is the area. When the displacement is equal to the distance, there is part of the time v

If the radius of the bottom circle of the cone is 8 and the length of the generatrix is 15, then the degree of the central angle of the sector in the side expanded view of the cone is______ Degree

The circumference of the bottom surface of the cone is 2 × 8 π = 16 π, and the degree of the angle of the center of the sector is 180 × 15 π = 192 °

What are the rules of removing brackets and adding brackets?

Before the brackets is minus, and after the brackets are gone, all the items inside will change sign,
The plus sign is in front of the bracket, and the sign remains unchanged after removing the bracket