# Posts by marcus

Total # Posts: 275

Inequalities
Two is greater than five? That's what I do not understand.. Thank you

Inequalities
solve (x-3)/(x+1) > 5 I get x < -2 every time, but it doesnt work when I plug it back in. (I plugged in -5)

Rational vs. Irrational
Okay thank you.

Rational vs. Irrational
Is 3.05313131313131313131313131... irrational or rational? Thanks.

Domain- Interval Notation
Thank you!

Domain- Interval Notation
Domain of g(x) g(x)= sqrt(3-(sqrt(25-x^2)) I got -5, -4, 4, and 5. I wrote it like [-5, -4] U [4, 5] I don't think that's right?

Chemistry
I'm working on a problem dealing with calculating the heat of vaporization for vapor pressures problem. By substituting the problems values into the Clausuis-Clapeyron equation I get: .642= (2.28x10-5) x Delta H vap (J/mol) However, from this point I don't know how to ...

Math
Same kind of problem. How to rearrange to put an equation in quadratic form. Example I'm given is 49.7= 2x^2 / (1.00-x)(2.00-x) which should come out to .920x^2 -3.0x + 2.0 but I can't figure out exactly how to get to there, especially how to get the x squared number.

Math
Stupid question time. I need to figure out how to rearrange equations to solve for x in my chemistry homework, which involves putting equations in quadratic form first. But I can't for the life of me remember how to "rearrange" them correctly. So what in the step...

physics
0,0 is the origin

physics
A proton is put on the positive Y axis a large distance (100km) from the origin. What is the minimum speed required in the - Y direction so the proton will just reach the point (0,20) cm?

College Physics
So what's the minimum speed ?

College Physics
0,0 is the origin there is no repelling charge

College Physics
A proton is put on the positive Y axis a large distance (100km) from the origin. What is the minimum speed required in the - Y direction so the proton will just reach the point (0,20) cm?

chemistry
A sample of propane C3H8 contains 13.5 moles of carbon atoms how many total moles of atoms does the sample contain?

Chemistry
The molal boiling-point constant for water is 0.51 degrees C/molal. The boiling point of a 1.00 molal solution of Ca(NO3)2 should be increased by: A.) exactly 1.53 or B.) Somewhat less than 1.53 This is how I worked the problem: Ca(NO3)2 dislocates into 3 mole particles. ...

Chemistry
Another proposed mechanism problem: H2O2 + I ---> H2O +IO slow H2O2 + IO ---> H2O + O2 + I fast Which of the following statements in incorrect? a.) IO is a catalyst b.) I is a catalyst c.) The net reaction is 2H2O2 ---> 2H2O + O2 I would choose B, since IO is shown as...

Chemistry
The decomposition of ozone may occur through the two-step mechanism shown below: step 1 O3 ----> O2 + O step 2 O3 + O ---> 2O2 The oxygen atom is considered to be: a catalyst or reaction intermediate? How am I supposed to be able to tell the difference between the two? I...

Chemistry
Which of the following solutes, dissolved in 1000g of water, would provide a solution would the lowest freezing point? .030 mol of BaCl2, CO(NH2)2, CaSO4, CH3COOH, or .030 mol of NH4NO3 Again, the steps needed to determine for the freezing point.

Chemistry
Which of the following solutes in aqueous solution would be expected to exhibit the smallest freezing-point lowering (assuming ideal behavior? 0.1 m NaCl .2 m CH3COOH .05 m Al2(SO4)3 .1 m MgCl2 .25 m NH3 What would be the steps to picking the right option? Because just picking...

Chemistry
Which of the following pure liquids is the best solvent for sodium fluoride? CCl4 C2C6 HCl BCl3 or PCl5 My guess would be either CCl4 or C2C6, I need to know the reasoning behind the correct answer.

Chemistry
In a given 1st order reaction A ---> products, the initial concentration of A is 0.40 M. What will be the concentration of A after 15 seconds if the half-life of the reaction is 3 seconds? I found the concentration to be 1.25 x 10-2 M But then how do I find the rate ...

Chemistry
Cyclopropane rearranges to form propene: CH2CH2CH2 --> CH2=CHCH3 by first-order kinetics. The rate constant is k = 2.74 x 10-3 s-1. The initial concentration of cyclopropane is 0.290 M. What will be the concentration of cyclopropane after 100 seconds?

Chemistry
The decomposition of N2O5(g) --> NO2(g) + NO3(g) proceeds as a first order reaction with a half-life of 30.0 seconds at a certain temperature. If the initial concentration [N2O5]0 = 0.400 M, what is the concentration after 120 seconds?

Chemistry
In a given 1st order reaction A ---> products, the initial concentration of A is 0.40 M. What will be the concentration of A after 15 seconds if the half-life of the reaction is 3 seconds?

Chemistry
2A + B2 + C --> A2B + BC Run # Initial Rate (M-1s-1) (A)o (B)o (C)o 1 1.6 x 106 1.2 M 1. x 10-2 M 1.0 M 2 1.6 x 106 2.4 M 1. x 10-2 M 1.0 M 3 3.2 x 106 1.2 M 2. x 10-2 M 1.0 M 4 6.4 x 106 1.2 M 1. x 10-2 M 2.0 M What would be the rate-law expression of the reaction above?

Chemistry
What is the vapor pressure of a aqueous solution containing 10 % (by weight) ethylene glycol (62 g/mol) at 25 °C. PH2O = 24.3 torr at 25°C?

Chemistry
When 1.150 grams of an unknown nonelectrolyte dissolves in 10.0 grams of water, the solution freezes at -2.16°C. What is the molecular weight of the unknown compound? Kf for water = 1.86°C/m. -2.16 x m/-1.86 = 1.16 1.16/ .010 kg of water= 116 1.150/116= 9.91 g/mol is ...

Chemistry
A solution contains 10.0 g pentane, C5H12, 10.0 g hexane, C6H14 and 10.0 g benzene, C6H6. What is the mole fraction of hexane? I figured the equation would be: ___ M Hexane x 10 Divided by 30 =Mole fraction of Hexane?

Chemistry
What mass of water must be used to dissolve 20.0 grams of ethanol, C2H5OH, to prepare a 0.0500 molal solution of ethanol?

Chemistry
What is the molality of an aqueous solution that is 10.0% ethanol, C2H5OH, by mass?

Chemistry
The rate of a reaction A ---> B is expressed by the rate expression rate=k(A)2. If the molar concentration of A is tripled, the rate of the reaction should increase by a factor of some many?

math
how do I write equation for the following? input a 20/28/36/44/52 output b 5/7/9/11/ ? ? is 13

Math
You have 2/3 bag of flour. Use 3/4 of the flour to make cookie dough. How much of the entire bag do you use to make cookie dough?

Math
The teacher asked Laura to give each student 2/5 sheets of paper. If there are 20 students in the class how much paper did Laura pass out?

GRAMMAR
WRITE AN ARTICAL ABOUT CALIFORNIA GOLD RUSH

chemistry
My chem book gives me the following Hess' Law example: Mg + 2HCl --> H2 MgCl2 Delta H1 MgO +2HCl --> H2O +MgCl2 Delta H2 H2 + 1/2 O2 --> H2O Delta H3=-68.3kcal The desired reaction is the formation reaction of MgO as follows: MgS +1/2 O2 --> MgO Delta H final= ...

physics
A weightlifter has a basal metabolic rate of 80.0 W. As he is working out, his metabolic rate increases by about 650 W. (a) How many hours does it take him to work off a 450-Calorie bagel if he stays in bed all day? (b) How long does it take him if he’s working out? (c) ...

precalculus
My book says a way for me to graph/plot points for my function is to write it in exponential form. For example. "Graph (fx)= log base 2(x-2) y=log base 2 (x-2) x-2=2^y x=2^y + 2 So now I can just plug any y value in to get my x value to graph my translated graph. So I was...

precalculus
When asked to sketch the graph of g(x)= -e^(x+1) +1, how do I turn this equation into exponential form? Or can I? I always get confused on what to do especially when I need to the x part of the equation out of the exponent.

precalculus
My book tells me to solve each exponential equation. I am given a lot of problems such as 6^x+1 = 4^2x-1 where I use In in the problem to help get my answer. However, in the same section, the book starts giving me problems such as 3(2)^x-2 +1=100 and .05(1.15)^x =5 etc. Where ...

precalculus
e^3x-7 x e^-2x =4e First step I get e^1x-7 =4e For the example in my book, the next step they divided by e. But I have no idea how to do this, or what involves?

precalculus
log_6(2x + 4)=2? 5 In x=10? log(x+25)=1+ log(2x-7)?

precalculus
No reason, basically the equation is supposed to read 3^log base 3^8?

precalculus
x= 3^log_3_^8 ? The log being in the exponent is throwing me off.

Precalculus
Solve (log x)^2 = log x Also, when will their be a possibility that an equation will have an extraneous solution? Like if you got two solutions for a log equation, will a negative solution for x automatically be extraneous?

Pre calculus
Okay, I'm really fuzzy about my log and exponential chapter. For example, solving some exponential equation such as e^3x-7 x e^-2x=4e I assume I start this equation by taking the natural log of both sides, but how will I know just by looking at an equation weather I need ...

science
What is the acceleration of a 50kg person is pushed with a force of 4N

chemistry
when Na compounds are heated, thy give off a light of 5890 A. If 1 x 10-4 mole of Na atoms each give off a photon of this wavelength, how many kilojoules of energy are given off?

chemistry
consider the following changes at constant temperature & pressure H2O(s) --yields-- H20(l); Delta H1 H2O(l) --yields-- H2O(g); Delta H2 H2O(g) --yields-- H2O(s); Delta H3 Using Hess's law, the sum of the deltas is a. equal to 0 b. sometimes greater than zero, sometimes ...

chemistry
since q= 100 mL x 4.18 x 8.01 =3348.18/.06= 55803. J to kJ= 55.803 should be the final answer, right? Because the answer key on my quiz says it's -55.8 kJ. I'm so confused because I thought for sure it would positive, especially since in the equation it says increases ...

chemistry
When 50.0mL of 1.20 M of HCl (aq)is combined with 50.0mL of 1.30 M of NaOH (aq) in a coffee-cup calorimeter, the temperature of the solution increases by 8.01 Degrees C. What is the change in enthalpy for this balanced reaction? HCl(aq) + NaOH(aq) --yields-- NaCl(aq) + H20(l) ...

chemistry
A 94.7 g sample of silver (s= 0.237 J/(g x Degree C)), initially at 348.25 Degrees C , is added to an insulated vessel containing 143.6 g of water (s=4.18 J/(g x Degree C)), initially at 13.97 Degrees C. At equilibrium, the finial temperature of the metal-water mixture is 22....

chemistry
I get -3113 as my answer when I plug in 30.6 as the molar mass when the teacher said it should be around -225 as the final answer?

chemistry
At constant pressure and 25 degrees C, what is delta H for the reaction 2C2H6(g) + 7O2(g) --yields-- 4CO2(g) + H2O(l) if the complete consumption of 11.3 g of C2H6 releases -586.3 kJ of heat energy? (11.3=.38 mol C2H6)

math
is 0.14 equal to 0.104

Art
If a painter paints 8 different pictures to get a better perspective and then only selects 1 picture to illustrate her mood: what would this be called?

Math
A basket containing 80 eggs weighs 2kg 300g. The same basket containing 60 eggs weighs 1kg 700g. Find the mass of the empty basket.

healthcare management
Write a 1,400- to 1,750-word paper on essential communication in a community crisis situation described in the scenario. Include the following in your paper: • The individuals or groups that will be communicating inside and outside the organization during this crisis ...

math
Fill in the blanks with the numbers that complete the sequence, and briefly explain the rule you used 2,3,5,5,8,7,11 _,_,_,17,_,_,_ 3,4,3,4,5,3,4,5,_,_,_,_,_,7 1,2,1,1,2,3,2,1,1,2,3,4,3,_,_,1,2,_,_,_,_,_,2

math
yes 13,15,17,19 thanks :)

math
that would give me 16 but that's not an odd number

math
Use algebra pieces and mental arithmetic to determine four consecutive odd numbers who sum is 64. Sketch and label your algebra piece model and explain how you solved the problem.

math
thanks i really appreciate it

math
what do you mean there are 6 wheels left over?

math
Levinson’s Hardware has a number of bikes and tricycles for sale. There are 27 seats and 60 wheels all told. Determine how many bikes and tricycles there are in the store

Math
gerald had a gross pay last wk of \$980.00, If his total deductions were 161.35, what was his net pay?

Cardiovalscular
Phonology refers to the science which treats A. blood disorders. B. vocal sounds. C. heart rhythms. D. nutritional deficiencies. MY ANSWER IS A

consumer math
2. Use the monthly payment table and this table to answer the following questions. Loan APR Years Monthly Payment Total Payment Interest \$6,700 13.5% 5 A B C \$8,720 12.5% 15 D E F \$20,230 11.5% 20 G H I Find A. (Points : 1) 3. Find B. (Points : 1) 4. Find C. (Points : 1) 5. ...

calculus
Actually, it's not homework. It's a practice problem that I don't even get credit for. I've done the problem multiple times but didn't think I should type up all my work for the wrong answers that I keep getting. I don't know who the other person is ...

calculus
If f(x)=x2+10, find and simplify the following: (a) f(t+8)= (b) f(t5+8)= (c) f(5)= (d) 5f(t)= (e) (f(t))2+8=

Algebra
The linear equation y=0.15x+0.79 represents an estimate of the average cost of gas for year x starting in 1997. the year 1997 would be represented by x=1, for example, as it is the first year in the study. similarly, 2005 would be year 9, or x=9 A) what year would be ...

algebra
42x^5 _____ 7x

Erica invests \$10,000 at 5% interest compounded annually. How much interest will Erica earn in 3 years

pre algebra with pizzazz 239
why didn't the circus managers want their human cannonball to quit?

statistics
Facebook reports that the average number of Facebook friends worldwide is 175.5 with a standard deviation of 90.57. If you were to take a sample of 25 students, what is the probability that the mean number Facebook friends in the sample will be 190 friends or more?

geometry
DEFG is an isosceles trapezoid. Find the measure of <E.

science
You have 10 ml of a 1:10,000 solution of hydrogen peroxide (H2O2). What is the molar concentration of the solution?

compostion and communiucation II
DO YOU THINK BLOGGING AND INCREASED EXPOSURE TO INFORMAL WRITING HAS AN AFFFECT ON STUDENTS ACADEMIC WRITING QUALITY.

Geometry
If AB=5x+2 and AC=12x-2, what is BC?

Maths C
lol! i have the same assignment and im having trouble aswell. I cant find anything on weddles rule on the internet and it is not in my textbook.

science
cslculate the molarity of a solution of 10.0g MgCl2 in a 300.0ml of solution

geometry
How many hours will it take a bicyclist traveling 17.6 feet per second to finish a 90-mile race? Round your answer, if necessary, to the nearest tenth.

geometry
XY bisects and is perpendicular to line segments AB and CD . AB = 96 inches, and line segment AP = 52 inches. What is the length of XY ?

algebra
Actually is does make sense. drwls misinterpreted the question. It's asking for a decrease of 400% over 10 year and NOT a percent decrease. This means, that for year 1, the cost of a cell phone drop by 40%. At year 2 it dropped by another 40%, and on and on until year 10. ...

Math
1) 2 + (-3) = ? 2 - 3 = -1 2) (-7)(11) = ? - ( 7 * 11) - - (77) so (-7)(11) = -77

Math
Owes is negative/ gives is positive -455 + 86 = - 369 -369 -107 = - 476 - 476 + 348 = -128 So, after all that, he owes the company \$128

algebra
what does the formula D=(b-c) represent

pre algebra
An area has been reforested. After 5 years , one of the tree is 2 meters tall. After six more years, the same tree is 3.2 meters tall. name 2 ordered pairs that can be used to to graph the information?

math
Max has the following colors of shirts: red, blud, green, yelllow, white, and orange. in how many different ways can he arrange the shirts in his closet?

math
On the fastest speedways, some drivers reach average speeds of 2 miles per minute. write the formula that gives the number of miles M that such driver would travel in x minutes. How would this driver travel in 38 minutes?

science
How many gallons of fossil fuel to make a gallon of each of the following? synfuel soy ethanol cellulosic electricity

biology
who made the first dna model and when

Chemistry
2. the pressure rises until a liquid-gas equilibrium is reached. A real life example of this is fire extinguishers which store CO2 as a liquid at room temperature at really high pressures. Im just a student, but I think that as the dry ice sublimes into gas at low pressures, ...

Chemistry
An ideal monatomic gas initially at 298 K and 1 atm pressure is expanded from a volume of 1 liter to 2 liters. Consider separately isobaric, isothermal and adiabatic expansions to accomplish this. In each case, calculate the following: a) The final temperature of the gas b) ...

algebra 1
Natalie made a mistake in the following problem. What line was the mistake made in? Show your work and give the correct answer. Line 1 6(4) ÷ 2 − 1 + 5 Line 2 6(4) ÷ 1 + 5 Line 3 24 ÷ 1 + 5 Line 4 24 + 5 Line 5 29

Geometry
Given triangleABC is congruent to triangleXYZ, if AB=3X-1, BC=5X+2, XY=7, and YZ=14, find X.

Ginny has a pumpkin with a mass of 4.8kilograms. If .9 of its mass is water, how much of its mass is water? How much is not water?

wordd
Compare and contrast your abilities as an academic writer now as opposed to when you began your studies at college using four comparatives and four superlatives within your responses, explain what has led to these changes