Fill in the appropriate prime number in brackets: 6 = () + (). If you are a friend, please help!

Fill in the appropriate prime number in brackets: 6 = () + (). If you are a friend, please help!

6 = 1 + 5 = 2 + 4 = 3 + 3, all prime numbers are only 6 = 3 + 3,

Fill in the brackets with the appropriate prime numbers
1.30=（ ）+（ ）=（ ）+（ ）=（ ）+（ ）
2.18=（ ）x（ ）x（ ） =（ ）+（ ） =（ ）-（ ）

1.30=（ 13）+（17 ）=（11 ）+（19 ）=（7 ）+（23 ）
2.18=（2 ）x（3 ）x（ 3） =（11 ）+（7 ） =（29 ）-（11 ）

Given 1 / A-1 / b = 1, find the value of fraction (2a + 3ab-2b) / (a-2ab-b)
2. Given X / 3 = Y / 2 = Z / 5, find the value of fraction (XY + YZ + ZX) / (x ^ 2 + y ^ 2 + Z ^ 2)
3. Xiaohui is sitting on the bus driving at a constant speed, and noticed that there are some billboards on the roadside evenly spaced. He uses his watch to look at several billboards passing by the window in one minute. He starts to look at his watch and ends to look at it at the center of two billboards, and multiplies the number of billboards passing by K in one minute, which is exactly equal to the kilometers of the car per hour, Please calculate the distance between two billboards (expressed in an algebraic expression with k)

1.1/a-1/b=1
(b-a)/(ab)=1
ab=b-a
(2a+3ab-2b)/(a-2ab-b)
=[2a+3(b-a)-2b]/[a-2(b-a)-b]
=(b-a)/(3a-3b)
=-1/3
2. Let X / 3 = Y / 2 = Z / 5 = K,
x=3k,y=2k,z=5k.
(xy+yz+zx)/(x^2+y^2+z^2)
=(6k^2+10k^2+15k^2)/(9k^2+4k^2+25k^2)
=31/38
3. With X billboards, there is x distance between two billboards
Km / min = x * k / 60
Distance between two billboards = (XK / 60) / x = K / 60

Given a (0,3), B (- 1,0), C (3,0), find the coordinates of point D, so that the quadrilateral ABCD is a right angle trapezoid (a, B, C, D are arranged counterclockwise)

As shown in the figure, a (0, 3), B (- 1, 0), C (3, 0), to make the quadrilateral ABCD right angled trapezoid (a, B, C, D arranged counterclockwise), if point D is the situation shown in the figure, let D (x, y), ad = (x, Y-3), CD = (x-3, y), from the quadrilateral ABCD right angled trapezoid, get: ad · CD = 0, and | OD | = 32

What is the maximum and minimum distance of the point trace line 3x + 4Y + 19 = 0 on the circle (x-1) ^ 2 + (Y-2) ^ 2 = 9?

Distance from center of circle (1,2) to straight line d = | 30 / 5 = 6
r=3
So the maximum distance = D + r = 9
Min = D-R = 3

It is known that the parabola y = - X & # 178; + 3 (M + 1) x + m + 4 intersects the x-axis at two points a and B, and intersects the y-axis at C. if point a is on the negative half axis of x-axis, point B is on the positive half axis of x-axis, and Bo = 4!

BO=4
Then x = 4 is a root of the equation y = - X & # 178; + 3 (M + 1) x + m + 4 = 0
So - 4 & # 178; + 3 (M + 1) * 4 + m + 4 = 0
So m = 0
So the analytical formula of parabola is y = - X & # 178; + 3x + 4

(if 2 (x + 4) - 5

∵2(X+4)-5

This paper describes the experiment of volt ampere characteristic curve of small bulb. Why can small resistance sliding rheostat make voltage change more obvious at both ends of bulb?

This is the partial action of resistance

Solving quadratic equation (x-1) ^ 2-4 (x-1) + 4 = 0 by factorization

(x-1)²-4(x-1)+4=0
[(x-1)-2]²=0
(x-3)²=0
x=3

How many days are there between September 6, 2009 and December 22, 2012?
As the title!

1203