賣女孩的火柴

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回覆: 4

2016-02-27 4:46 pm

　C(2n,n) - C(2n,n-1) = (2n)!/[n!(n+1)!] = ___________.?

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回覆: 2

2016-02-27 4:39 pm

The line 4x+6y =0 and 2x+4y=0 intercepts at N. Find the equation of the line through N perpendicular to The line x+2y=0?

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回覆: 5

2016-02-27 4:37 pm

When 3 dice are thrown, the probability of not getting any 2's is?

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2016-02-27 3:26 pm

Calculate the concentration of SO2− present 3 in 0.125 M H2SO3. Answer in units of mol/L.?

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回覆: 1

2016-02-27 3:31 pm

The function f(x)=x^3+ax^2+bx+c has a relative maximum at (-3, 25) and a point of inflection at x=-1. find a,b, and c?

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回覆: 2

2016-02-27 3:18 pm

can you help me with this question?

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2016-02-21 2:32 am

What is the equilibrium constant Kfinal for the following reaction?

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2016-02-21 2:33 am

What is the equilibrium constant Kfinal for the following reaction?

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2016-02-27 4:59 am

Write and equilibrium constant expression for the following reactions: A.) 2N2(g)+3BR2(g)=2NBr3(g) B.) C(s) + O2(g)=CO2(g)?

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2016-02-27 5:26 am

What is the percent by mass of an aqueous solution that is 1.5m ammonium sulfate?

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2016-02-27 5:57 am

why is h2so4 added to so3 in contact process?

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回覆: 1

2016-02-27 6:08 am

Using hybridization, explain how carbon forms both sigma and and pi bonds in graphite, but only sigma bonds in the diamond form?

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2016-02-27 8:20 am

Calculating heat given off by burning magnesium?

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回覆: 5

2016-02-27 11:07 am

the cage have chicken and rabbits,total is 35 heads,94 foots~ question is there are how many chickens and how many rabbits?

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2016-02-27 10:50 am

Why Ethanol can react with water while propanol cannot?

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2016-02-26 8:09 pm

Identify the major force between acetone and chloroform.?

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回覆: 3

2016-02-26 7:52 pm

How is (5/x)+(3/2x)=(6/(x+2) solved ?

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2016-02-26 7:32 pm

Chemistry Question Easy?

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2016-02-26 7:44 pm

Write an equation for the reaction in which H2C6H7O5−(aq) acts as a base in H2O(l).?

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2016-02-26 6:30 pm

Calculate the equilibrium concentration present.?

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2016-02-26 7:00 pm

A hydrated form of copper sulfate (CuSO4·x H2O) is heated to drive off all the water.?

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2016-02-26 7:13 pm

What would the products of this reaction be?

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2016-02-26 7:03 pm

Chemistry Question?

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2016-02-26 6:48 pm

An artifact has a carbon 14 to carbon 12 ratio that is 1/4 the carbon-14 to carbon-12 ratio of a similar modern object. How old is it?

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2016-02-26 6:41 pm

Chemistry Help!!?

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2016-02-26 6:31 pm

Chem Question! Please Please Help and explain!?

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回覆: 3

2016-02-26 6:28 pm

Simplify this expression.?

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2016-02-26 5:49 pm

Which of the following cannot be the formula of an alkene?

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回覆: 3

2016-02-26 6:03 pm

What is the derivative and the anti derivative of lnx?

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2016-02-26 5:56 pm

Help with math?

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2016-02-26 5:05 pm

what is 177 divided by 3:4?

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2016-02-26 4:50 pm

Help balance please!!! H2O + As + HClO3 ----> H3AsO3 + HClO?

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回覆: 3

2016-02-26 4:25 pm

Statistics Probability Question?

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回覆: 6

2016-02-26 4:32 pm

simplify sin(pi/6 +x)+sin(pi/6 -x)?

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回覆: 4

2016-02-26 4:26 pm

Statistics Probability Question?

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回覆: 1

2016-02-26 4:19 pm

Mass of water heated?

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2016-02-26 4:19 pm

Raising temperature, chemistry?

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2016-02-26 4:13 pm

How many significant figures will the answer to the following problem have? You do not have to solve the problem.?

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2016-02-26 4:04 pm

In an experiment, 1.6 grams of Sr-90 was buried in 1952. How much of this sample is still Sr-90 in 2008?

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回覆: 3

2016-02-26 4:03 pm

How to reduce silver from silver nitrate by natural reducing agent ?

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2016-02-26 4:01 pm

Use proportional reasoning to solve. 3/7= n/28?

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2016-02-26 3:30 pm

Math logarithm problem?

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2016-02-26 3:17 pm

Find the value of k, for which one root of the quadratic equation kx2-14x+8=0 is six times the other.?

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回覆: 5

2016-02-26 3:08 pm

if element 17 in a halogen where you would expect to find element 18?

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2016-02-26 3:05 pm

Acetic acid (C2H4O2) is the active ingredient in vinegar. Calculate the mass percent composition of carbon in acetic acid??

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2016-02-26 3:03 pm

A cylindrical glass is 3 inches in diameter and 6.5 inches tall. How much water can the glass hold when full.?

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2016-02-26 2:52 pm

what volume is occupied by 25 g of oxygen gas at a pressure of 733 mmhg and a temperature of 30.5 degrees?

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2016-02-26 2:41 pm

Which is the limiting reactant in the following chemical equation? Zn + 2HCl >> 2 ZnCl2 + H2 with 10 moles of Zn and 15 moles of HCl?

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2016-02-26 11:14 am

Determine the pH of the following solution?

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2016-02-26 11:42 am

What is reducing property? Explain with reference to oxygen.?