In class 5 (6), female students account for 4 / 9 of the class, while male students account for 5 / 9 of the class?

In class 5 (6), female students account for 4 / 9 of the class, while male students account for 5 / 9 of the class?

4/5

There are 12 more boys and 12 more girls in class 5 (3) than in the whole class. How many students are there in class 5 (3)?

A: there are 45 students in class 5 (3)

Sorry to disturb you
Try to make this sentence as authentic as possible. But don't use complicated grammar. It's better to provide formal and oral (if any)
I didn't ask the question well.
Illiterate learning English 18:29:46
I forgot to say a few words. Excuse me / sorry to disturb you?
czcy1188 18:42:11
Sorry to have disturbed you
Sorry to disturb you
I investigated on the Internet, it seems that all three of them are right, but the usage is different. I didn't say hello.

sorry to disturb you
English and American Idioms

Proof: when n is an integer, the square difference (2n + 1) - (2n-1) of two consecutive odd numbers is a multiple of 8

(2n+1)^2-(2n-1)
=4n^2+4n+1-(4n^2-4n+1)
=4n^2+4n+1-4n^2+4n-1
=4n+4n
=8n
Because n is an integer
So 8N is a multiple of 8
So the difference between two odd squares is a multiple of 8

How to calculate dy / DX = u + XDU / DX formula

Let y = UX
On the same differential on both sides of an equation
dy=xdu+udx
Divide DX by both sides
dy/dx=u+xdu/dx

Why 32 * 69 = 23 * 96; 84 * 24 = 48 * 42; 13 * 93 = 31 * 39? What's the rule?

Multiplication of two tens of bits is equal to multiplication of one bit
13 and 93 24 and 84 23 and 96 12 and 63 12 and 42 12 and 84 14 and 82 13 and 62
23 and 64 24 and 63 26 and 93 34 and 86 36 and 84 46 and 96 should be on these

People's education press first day mathematics volume 143 exercise 4.3 No. 10 sorry did not point
If there is a graph, ob is the bisector of AOC, OD is 1 of Coe. AOB = 40 ° and DOE = 30 ° then what degree is Bod?
2. What's the value of ∠ AOE = 140 °∠ cod = 30 °?

(1) 40 ° + 30 ° = 70 °
（2）140°－30°×2＝80°
80 ° 2 = 40 ° AOB is 40 degree
Do you need those because of all? If you want, I'll give them to you again

Find the tangent plane of the surface x ^ 2 y ^ 2 Z ^ 2 = x so that it is perpendicular to the intersection of the plane x-y-0.5z = 2 and the plane X-Y-Z = 2

The transcription of the title is incomplete. From the perspective of keyboard typing, the curved surface seems to be X & # 178; + Y & # 178; + Z & # 178; = X. here is the solution;
The tangent plane of space surface can be directly derived from the surface equation f (x) = 0 to obtain the normal vector {&; F / &; X, &; F / &; y, &; F / &; Z};
If f = x & # 178; + Y & # 178; + Z & # 178; - x = 0, then f / & 8706; X = 2x-1, & 8706; F / & 8706; y = 2Y, & 8706; F / & 8706; Z = 2Z;
So the normal vector of tangent plane is {2x-1,2y, 2Z};
The equation of the intersection of two planes is: X / k = Y / k = Z / 0; just let 2Z = 0, 2x-1 = 2Y = k; substitute this relation into the surface equation:
X & # 178; + (x - 1 / 2) &# 178; = x, the solution is x = (2 ± √ 2) / 4; y = ± √ 2 / 4;
There are two tangent planes (tangent points): [x - (2 ± √ 2) / 4] + [y - (± √ 2 / 4)] + 0 * z = 0, that is, x + y = (1 ± √ 2) / 2;

Comparison of zero degree water and zero degree ice
The distance between water molecules in ice a is small
The potential energy between water molecules in ice B is small
The kinetic energy of water molecules in C ice is small
There is a large space for the thermal motion of water molecules in ice D

A gas liquid solid, the intermolecular distance decreases in turn, a is correct
B ice into water is endothermic, which means that the internal energy of water is greater than that of ice. The temperature reaction is the sum of kinetic energy of all molecules doing irregular thermal motion, which is also zero degree. Therefore, the kinetic energy of ice and water is the same, so the potential energy of water is greater than that of ice. B is correct
C the same temperature, so the same kinetic energy, so wrong
D water molecular gap is larger than ice water molecular gap, see a, so wrong

The lithium-ion batteries used in mobile phones are marked with "3.6V & nbsp; 900mA · H", where Ma · h is a physical quantity______ Please estimate the storage capacity of the battery______ J. If the current of the mobile phone is about 6mA, the fully charged lithium-ion battery can be used continuously______ h．

Ma is the unit of current, h is the unit of time, then we can know from q = it, Ma · h is the unit of charge; from w = uit, this kind of battery can store electric energy: w = UQ = 3.6V × 900 × 10-3a × 3600 = 11664j, from I = QT, this kind of fully charged lithium-ion battery can be used continuously for mobile phone: T = Qi '= 90