Math-Reiny this one is more confusing to me :(

196,200 results


How do I find a variance for a set of numbers {1,16,8,17,12} I got that variance-34.2, but I'm unsure. Any help? Thanks. math - Reiny, Sunday, January 24, 2010 at 8:16pm look at his page. Reiny - April, Sunday, January 24, 2010 at 8:25pm I looked at that page and did my ...

Math (Reiny??)

Mrs. Reiny ... As in Harris County Mrs. Reiny?

To Reiny

Reiny could you please check my Calculus post below, it says Calculus--Reiny.


I have an exponent properties test tomorrow, its our last one before the final, so its important, but anyways, there is one question on the review that is confusing me. Could you please help? Here it is : (2y2x7)(-xy)(9x-3y) I don't know if the exponents showed up, but the ...

Reiny! Reiny! Reiny! Answer Check and HW Help!

Translate to a system of equations and solve: 1) The sum of two numbers is 36. One number is 2 more than the other. Find the numbers. Answer: (17,19) 2) Find two numbers whose sum is 66 and whose difference is 18. Answer: (37,29) These ones I am not sure of: 3) The difference ...


What is implicit in what would be the steps in solving it. I read my textbook but it seems very confusing. 1) Differentiate both sides with respect to x 2) Realize that y is a function of x 3) Solve for y Plus the d/dx notation made it even more confusing...

Reiny+ In need of help

Hey Reiny, could you please take a look at my expo growth and decay post? Thanks alot.


Reiny I think I have found out the rectangle problem. Could you check and see if Ive got it correct?

Reiny! Reiny! Reiny!

1. Oanh walked from her home to the grocery store at 3 mi/h and jogged home at 6 mi/h. Her total round trip was 15 minutes (1/4h). How far from Oanh's home is the grocery store? (use an equation to solve this) Help, I am totally clueless on this.

Math (need more help Reiny)

Ok i figured out the first part that i need to square the numbers so after 4 it will be 5x5,6x6,7x7,8x8and 20x20 to make up the second column, what i don't get is the 3rd one, how do i come up with the number of white triangular shapes used?


To Reiny: Hi, thank you for your time Reiny and your info. I am so sorry but on the first one I accidentally put 0 where I should have put =9. In other words, the first equation should have said (9n+1)squared =9. Really sorry to have taken up your time with the wrong equation...


Evaluate:|12 5 -2| |-3 0 1| |-5 4 2| It's going to be really confusing if I post my work. I got -127 from all the confusing things I did


reiny why are you so smart thanks for aswering my question

Math-Reiny this one is more confusing to me :(

A survey of vegetable gardeners showed the following: 63 grew tomatoes 26 grew cucumbers 38 grew zucchini 18 grew both tomatoes and cucumbers 22 grew both tomatoes and zucchini 19 grew both cucumbers and zucchini 14 grew all three types 18 grew none of these three (a) How many...

Urgent math question for Reiny

Find the value of the expression below for r=4 and t=2.... t^3-r+20 divided by r 9*** 72 6 40 Ok, Reiny you said my answer9 was originally wrong, however when I looked at the work you did and you put in parenthesis() question is why, because the original expression didn'...


I understand how to do these kind of problems except this one. Write the equation that has the given roots. Roots: 3 with multiplicity of 2, -5, 0 with multiplicity of 4. By the way I understood the help that I got earlier, but this problem seems to be more confusing.

Math thanks, Reiny

Thanks Reiny!

math help

Thank you for helping me with the last problem Reiny and Bosnian. However, I have one more problem that I need help with please and I have no idea how work the problem. I used an on line calculator to get the answer. It didn't give an explanation on how to do the problem ...

sir steve help me reiny reiny

2) A quality of identical plastic books weigh 10.98kg ,if each book weighs 54.9g .How many books are there


Hi reiny i just wanna say thank you for always answering my questions thanks for always helping me <3 thank you may god bless you


But I am getting more and more confused. -3-3x=-9????? and x/6=-24 but the there is a negative sign like x - - =-24 6 I know I am over thinking this,but I am confusing myself on these two???

URGENT~MATH For Steve or Reiny

For questions 5-7, find the solution to the system of equations by using either graphing or substitution. 5)y=6-x and y=x-2 (1point) (2,4) (-4,2) (4,2) no solutions 6)y=2x-1 and y=x+3 (1point) (4,7) (7,4) (-7,-4) no solutions 7) y=4x and y+x=5 (1point) (-4,1) (1,4) (-3,2) (2,3...


thanks reiny--but i'm in 6th gr and we r not studying powers..can you help me with a simpler answer without powers?

Math: Reiny

I already posted this question, and Reiny had a question about the question. How many square units are in the region satisfying the inequalities y>=(x) and y<=-(x)+3? Express your answer as a decimal. * the () are absolute value signs. •Math - Reiny, Wednesday, ...


how I change 28/9 to a mixed or whole number divide 28 by 9 to give you 3 with a remainder of 1. so 28/9 = 3 1/9 (three and one ninth) Thank you Reiny


Calculus - Reiny, Friday, December 23, 2011 at 6:59pm I read that as (4a^2-1)/(4a^2-16) * (2-a)/(2a-1) , my brackets are necessary = (2a+1)(2a-1)/( 4(a+2)(a-2) * (2-a)/(2a-1) the (2-a)/(a-2) are opposite, they will give you the -1 so.. = -(2a+1)/(4(a+2)) , again you have to ...


how does shifting the point of view [third person to first person] change the effect on the reader It's very confusing. If a story or essay starts out in 3rd person, the reader picks up on that and expects that to continue -- a shift to another POV is confusing and could lead ...

series maths steve reiny bob reiny steve!!!

if p is the nth term 8+20+52+.....+p evaluate the sum to n-of the series plz show step

Reiny!!!! math help

We understand how to do the questions now and we are really glad n thankful, but the graphing portion of it is confusing. Continuation of the function. The teacher wants us to plot the points from the different parts of the questions we answered and with your help we graphed ...

Algebra-Reiny please explain this

Hi Reiny, I posted this problem earlier and you responded but I don't get the reasoning- The problem was -2log8(x+1) = -8 you said multiply by -2 and then you put log8(x+1)=4(wasn't that dividing by -2) log8(x+1)^2 = 8 (how did you get to the power of 2 and =4 became =8 x+1 = ...

Thank you Jiskha and Reiny

I just wanted to write a post to thank everyone who helps out. I haven't found people to be very grateful on this site so I thought i'd take a moment to tell you how awesome you guys are. Special thanks to Reiny for all the helpful math tips. You have helped me through a lot ...


Posted by connie on Monday, July 20, 2009 at 11:56pm. Find the indicated outputs for f(x) = 2x²-4x f(0)= ____? f(-1) =____? f(2) =____? Responses math - Reiny, Tuesday, July 21, 2009 at 8:00am f(0) = 2(0)^2 - 4(0) = 0*0 = 0 f(-1) = 2(-1)^2 - 4(-1) = 2(1) + 4 = 2 + 4 = 6 now ...

To: Reiny

Please help me on my question, no one helped me...

to reiny

Reiny i got (x+5)(x-3) x=-5 or x=3

Pre Calc (For Reiny)

Thanks so much your method worked perfectly! My solution was: the remaining zeros were 5+2i, 3, and -4 I have one question that's bugging me though, why is it that synthetic division did not work for me? I thought that long division and synthetic division were both ...

Pre-Calculus - Reiny

Reiny you helped me with this logarithm yesterday: How did you write it out as log2 ( √A / B^3 ) Laws of logarithms combine, write as a single logarithm Need help on this question please, Im stuck, don't know where to go abouts from here: I did it on paint and uploaded ...

7th Grade Math

I do know how to find the area of a square and rectangle, but how do you fing the area of a rhombus. (that is at least what it looks like.) The shape I'm talking about is like a rectangle but it looks like one side got stretched to the left. (sorry if I made that even more ...

MATH (to Reiny)

I tried to simplify it with the second fraction by multiplying the top and bottom by "r" and i didn't work. Well at least I don't understand how to get there. Can you please just explain how... n!r/(n-r-1)!(r-1)!r goes to n!r/(n-r+1)!r! I get one put of it, that r x (r-1)! = r...


Mrs. Hart, at age 65, can expect to live for 25 years. If she can invest at 5% per annum compounded monthly, how much does she need now to guarantee herself $900 every month for the next 25 years? math - Reiny, Friday, April 3, 2015 at 3:05pm Present Value = 900(1 - 1.0041666...


an estate valued at $62,000 is left by a will as follow:to each of two grandchildren a certain sum,to the son twice as much as to the two grandchildren together,and to the widow $2,000 more than to the son and granchildren together. How much goes to each? I tried by reading ...

7th grade-Algebra Worth Problem

Please show equation and solve for the following 1. Lyn's age is 8 years less than 15 times the age of her niece Elizabeth. If the sum of their ages is 24, what is Elizabeth's age ( Let e= Elizabeth's age) 2. Bob is renting a canoe for $20, plus $9.75 per day. How mant days ...

Math( Attn: Reiny)

1. A rental business charges $12 per canoe and averages 36 rentals a day. For every 50-cent increase in rental price, it will lose two rentals a day. What price would yield the maximun revenue? I was told the answer by Reiny, but I couldn't get the right answer. I found the ...

Maths - Reiny

Show that the equation 3x^2 - x^3 + 3 = 0 can be rearranged to give: x = 3 + 3 ---- x^2 x^3 = Divide by ? = x = 3 + 3 ---- x^2 Using Xn+1 = 3 + 3 with x0 = 3.2 ---- x^2n find the values of x1 x2 and x3? What to the values of x1 x2 and x3 represent? The represent estimates of a...

maths steve reiny bob reiny!!! Help

If line 2x+y=-3 and x-2y=1 form the sides of a rectangle whose other sides meet at the point (3, 4), find the equations of the other sides and the area of the rectangle plz help show solution step

3 grade math ms sue

Name the lengths of the sides of three rectangles with perimeters of 12 units. Use only whole numbers. My son did -2-4-2-4 And one more 1-5-1-5 And one more 3-3-3-3 And I need one more rectangles number how you can make


Dear Reiny! U r a life-saver! Is there a short cut to how can I set the question or change word problems into math one? It seems that this is my problem! Also, why did my way worked as well with different answers? My answers satisfied all equations as well. Many thanks.


Thank you Reiny, Why I have to divide 632/1.05? I was dividing 632/0.05, I need to understand for future similar problems, I really appreciate your help, I finished school almost 30 years ago, I decided to go back to school an obtain a degree, I try my best but so many years ...

hello reiny damon steve can you help me physics

Find the Gravitational potential at a point on the earth's surface. Take mass of earth as 5.98*10^24kg, it's radius as 6.38*10^6m and G=6.67*10^-11Nm^2kg^-2. Plz i need sir damon and steve including reiny to show me step and solution plz

Calc I (@Reiny)

y = x^3 - 8x^2 + 6x -2 has a slope of 6 at two points, what are the coordinates? I used Reiny's way to help solve this answer. Please check if I've done it correct: y'= 3x^2-16x+6 3x^2-16x+6=6 3x^2-16x=0 x(3x-16)=0 Solve for x's x=0 3x-16=0 ~> x=16/3 Plug x values to ...

Calc I (@Reiny)

y = x^3 - 8x^2 + 6x -2 has a slope of 6 at two points, what are the coordinates? I used Reiny's way to help solve this answer. Please check if I've done it correct: y'= 3x^2-16x+6 3x^2-16x+6=6 3x^2-16x=0 x(3x-16)=0 Solve for x's x=0 3x-16=0 ~> x=16/3 Plug x values to ...


To find the weight of the gold in a 22 karat gold object, multiply the object's weight by 0.917. To find the weight of the gold in an 18 karat gold object, multiply the object's weight by 0.583. A 22 karat gold statue and a 14 karat gold statue both weigh 73.5 ounces. Which ...

dr bob

I am still confused by the last one CO3^2- You were nice enough to do a diagram and then the expalnation for what else I needed to do was so confusing - I am at study hall and this is my last one


If it says: "five less than three times a number is 20 More than half a number" would the equation be 3n-5=n/2+20? If so what would the answer be? Please help this is a bit confusing!

steve reiny reiny damon probability

buses arrive at the bus stop at 15min interval starting from 7am in the morning. If a passenger arrived at the bus-stop at a time that is uniformly distributed between 7 and 7:30am. what is the probability that the passenger waits less than 5minutes for a bus

10th grade math

1.548937075 x 10 to the 12th. round the number to 3 significat figures. I thought I would respost this because the other one was getting confusing


This is a confusing problem to me also, can someone please help me? What are the odds in favor of getting at least one head in three successive flips of a coin?


A simple sentence: A) Can be reversed and still mean the same thing. B) Expresses one complete thought with one subject and one predicate. C) Expresses one or more complete thoughts with one or more subjects and one or more predicates. D) Is easy to understand. My answer is C


An equation is not a function if even one x value produces ____ corresponding y value(s). one less than one more than one zero for a my guess is more

reiny steve reiny damon!!! Damon help maths

If P(x) and Q(x) have a common factor (x- h),prove that (x-h) is also a factor of P(x)- Q (x).find the possible common factors when P (x)=ax^3 + x^2 - 15x - 18 and Q(x)= ax^3 - 14x - 12.also find the corresponding value of a. Plz show me step of work

Physics I

I have this vector that is confusing me I know what I need to do but the components of these vectors are confusing me. Problem: You are standing at point with coor dinates (1m, -1m, -2m) another erson is at r(t)=(8m)i - (3m/s^3) t^3 j + (4m/s^2) t^2 k Find distance between you...


Why do you have to use estimation to find the number of triangles you need for the string? I was wondering why this question is quite confusing and i was wondering if you can explain it to me in a way i can understand it. I'm not looking for an answer just a more simpler view ...

cynthiavariation 2(steve,reiny,reed)pls I need help!

yea! D question was d one u asked me 2 put d first height!

Math @Reiny

Did I do #2 right? 2.) (1-2i)/2i (1-2i)/2i = (1-2)/i x i/i = (1i-2i)/i^2 = (1i+2) =2+1i


Please help as this is so confusing tome! 25. In addition to the nucleus, cytoplasm, and cell membrane, a single neuron possesses A. one dendrite and several axons. B. several dendrites and one axon. C. many nuclei and one neurilemma. D. one nucleus and many neurilemma.

Math w/reply

Hey there, just need help with these two. I need someone to help explain them to me/break them down. 1. gr 1/100=_____mg Answer: 0.6 2. 0.3mg= gr_____ Answer: 1/200 3. gr iii /ss= ______mg Answer: 210 Thank you in advance! *** REPLY: I did not get these answers. These are the ...

Reiny or Damon or Bobpursley

Express the series 11 + 18 + 27 +...+ 171 using sigma notation. Usually you would take 27-18 and that's the step between numbers, right? (I think its the k-value?) But 27-18=9 and 18-11=7. Are we stepping by k+2 here? Like k, k+2 k+4, k+6...? Please help me. I'm not confident ...

Pre-Algebra [repost for Reiny]

In my last post for #1, I asked my teacher and she said that it's actually k=30 . Could you have gone wrong somewhere? That's the only one. -MC


#1 (1/sinx)(sin^2x + cos^2x(sinx/cosx) )/(sinx + cosx) = (sinx + cosx)/(sinx+cosx) = 1 Reiny helped with this question but I don't how Reiny did it. Please explain

Math Reiny

AmI doing this right? Multiply (a+1/2)(a+1/3) a^2+1/6


dear reiny i am sim who posted 4 questions this morning i am in dubai and my final examinations are after 13 days and by the way those questions were not my homework or assignment those were some sums which we get on our school website and i had a doubt in those questions but ...


.50 - x / x = 3.20e-1 I need to solve for x. I was going to do .50 X 3.20e-1 and then take the square root but this is not correct. I am not sure what to do. Thank you for your help. Math(Please help) - Reiny, Tuesday, April 17, 2012 at 3:18pm You probably meant (.50 - x)/x = ...


Order of Magnitude (I'm not quite understanding it) 1) trying to 0.0000000734 estimated as the product with a single digit power of 10.*No multiple choice* 2) Trying to find the numbers that a greater than 7 x 10^-4 (Choose more than one answer type question) - 8 x 10^-4 * my ...

Algebra 2 to Reiny

in the one you helped me with, where did this come from: Where did this part come from? - (sin^2Ø + cos^2Ø)


When using a line graph, why is it inportant to only graph 1 - 3 series of data? A line graph in Microsoft Excel will not allow you to graph more than 3 series of data. It will not show changes over time of you use more than 3 series of data. The lines are too thick to use ...

To reiny: Regarding math question

Would the answer be d then??!!

is that the area of big or small triangle?


@ reiny. . . 9x^4-24x^3+16x^2. .i have done it bt i want you to do it 4 me to confirm


I need to change this number to a percentage, rounded to the nearest tenth. 1350-1010/1010=.336633663 would the answer be 3%? this one is confusing to me for some reason

Chemistry(Please check)

.50 - x / x = 3.20e-1 I need to solve for x. I was going to do .50 X 3.20e-1 and then take the square root but this is not correct. I am not sure what to do. Thank you for your help. Math(Please help) - Reiny, Tuesday, April 17, 2012 at 3:18pm You probably meant (.50 - x)/x = ...

German help - Reiny

#3 was supposed to be.... Mutters und Vaters Kinder sind A. meine Cousins B. mein Geschwister C. meine Schüler. D. meine Geschwister.***** This is the one I typed wrong last night - sorry about that...not sure on this one but I chose D....? Thanks for your help


how are and 3 4th bours and the distance traveled in 2 3 4th hours represented in the table?how are they shown on the graph? Having read the next four or five posts, I suggest you do two things: 1. Start over and write a complete question for each post. Fragments of questions ...


In a pseudopythagorean triangle, the sides are all integers and the sum of the square roots of the sides equals the square root of the third side. How many pseudopythagorean triangles are there. A. none B. 1 C. 2 D. more than 2 this is such a confusing question

Morse Code Please Answer!

My book doesn't explain how, for example, if D was --. and O was .-. than how would they tell the end of the D from the beginning of the O? Did they pause between letters? But then how would they know the difference between a "new letter" pause, and a "new word" pause. Could ...

Math - Odds

If you toss three coins, what are the odds in favor of getting exactly two tails and one head? A. 3:8 B. 3:5 C. 5:3 D. 8:3 can you explain this? i can do odds but this is confusing me.


thanks reiny for the help but can u tell me the domain of f g and fog in binary form? thanks

math (Reiny please)

how would i do these problems: 6. xsquared + 2x -7 =0 7. 6xsquared - 2x -1 = 0


We, my roomates and I, keep getting replies saying stop posting under more than one name. We are not posting under more than one name we are all different. We all live together and only have this common computer at the moment, but we are more than one person and we love this ...


I already posted this question and Reiny answered it, I just wanted to clarify my answer Problem: If f(x) is a polynomial of degree 4, and g(x) is a polynomial of degree 2, then what is the degree of polynomial f(x)-g(x)? Reiny: so f(x) has to contain an x^4 term and g(x) does...


Can you reply to my last math+log post =) thanks. I'm going to be having alot of math questions today.

To Reiny, math helper

can you look at my post, its just 4 math terms I need to figure out, please help


Thanks for the answer Reiny, could you explain the way you solved the factor of 21y^2+38+5


Reiny can you show me how to check this problem. 5a^8-20a^7-25a^6 =5a^6(a^2-4a-5) =5a^6(a^2-5a+a-5) =5a^6(a(a-5)+1(a-5) =5a^6(a-5)(a+1) (answer)


On the earlier questin would the speed be faster not slower?


I think you are a math tutor, could u help me with my problem?

ap biology again

In order to answer a question I must use this information but I find it very confusing. The restriction enzymes of bacteria protect the bacteria from succesful attack by bacteriophages, whose genomes can be degraded by the restriction enzymes. The bacterial genomes are not ...


Another one, sorry! =P This stuff is really confusing.. Why doesn't friction depend on surface area?

Biology - fossils

my sister Shreya be sick so i posting her biology questions. one question ask hw did creationists explain fossils. she write this be about noah's flood but what be noah's flood? i look up on internet for her and there be too much confusing words. i only be able to make out ...

Algebra II

I solved one of these sigma notations and had Reiny check it in an earlier post but this one totally befuddles me- Which of the following terms would not be in the series generated by the expression: 5 Signma symbol (k^2-5k+2) k=2 the choices are 2, -2, 4 or -4If you could ...

math (A question for Reiny)

THANK YOU SO MUCH for the help with magic squares! But I have one quick question- how can I show my work! I have to show my work or I receive like 1/2 credit.


you have one penny one nickel one dime and one quarter. how many different amounts of money can you make using one or more of these coins ... please


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