Tutors Answer Your Questions about Linear Algebra (FREE)
Question 56273: The problem is:
Suppose that a lot costs $60,000 and a builder charges $84 per square foot of living area in a house. How big, to the nearestr square foot, is a house that can be purchased for $180,000?
What I've tryied using so far is  , and have come up with three answers... 2143 square feet, 2857 square feet, and 1429 square feet. Which one (if any) is right?
Click here to see answer by funmath(2933)  |
Question 56444: I thought I could add the exponents but the answer didn't come out right. Can anyone help?
x^2 - 4 multiplied by x^2+5x+6
________ ___________
x + 3 x^2 + 4x +4
These two fraction are multiplied together. x^2 - 4 over x+3 multiplied by x^2 + 5x + 6 over x^2 + 4x +4
hope that is clear enough. it doesn't seem to hold the places.
Click here to see answer by stanbon(75887) |
Question 57549: "fashion furniture makes two kinds of chairs; rockers and recliners. two machinges a and b are used. machine a is limited to 20 hours per day. machine b is limited to 15 hours per day. machine a takes two hours to make each rocker and four hours to make each recliner. fashion furniture makes a profit of 12$ on each rocker and $10 on each recliner. how many of each type of chair should they make?"
Click here to see answer by stanbon(75887) |
Question 57546: I needed to solve this problem and get the solution set:
x^4 - 20x^2 + 64 = 0
What I have so far is:
w^2 - 20w + 64 = 0
(w - 16)(w - 4) = 0
w - 16 = 0 or w - 4 = 0
w = 16 or w = 4
x^2 = 16 or x^2 = 4
x = +/- square root 16 or x = +/- 2
Now I want to know how do I get the proper solution set from my solution. I mean waht is the solution set?
Click here to see answer by phillv(13) |
Question 52495: 4x+2y=8 y=2x+1
4x+2(2x+1)=8 y=2(8x-7)+1
4x+4x+1=8 y=16x-7+1
8x+1=8 y=16x-8
8x-7
Thats all i could figure out i don't know how to simplfy it because we are doing substitution. any help would be greatly apperiated. thank you.
Click here to see answer by hayek(51) |
Question 58328: A shoe mfg. makes outdoor and indoor soccer shoes. There is a two- step manufactoring processes for both kinds of shoes. Each pair of outdoor shoes require 2 hours of processing in step one, 1 hour in tep two, and produces a profit of $20 for the company. Indoor shoes require 1 hour of processing step one, 3 hour in step two and produces a profit of $15 for each pair. The company has 40 hours of labor per day avaiable for step one and 60 hours of labor per day available for step two. How many pairs of each type of shoe can be produced per day to maximize profit.
Click here to see answer by Nate(3500) |
Question 58455: Here is a function that I have been dealing with at work:
Y(x) = –3.3x2 + 0.5x + 300.
I need to use this function to tell researchers what value of x produces the maximum output signal for an MRI machine, Y. Also, since everyone’s MRI machine is not exactly the same as mine, I want to give them a range of x values that will produce nearly the maximum output Y. So, here are the questions:
1. What is the x value when Y is at its maximum value?
2. What is the maximum value of Y?
3. Since negative Y values are impossible for operating the MRI machine, what is the range of x values for Y to be greater than or equal to zero?
4. What is the range of x values where Y is at 90% of its maximum value?
5. Plot Graph showing all of the above information.
Click here to see answer by stanbon(75887) |
Question 58966: You have a green candle 12.4 cm tall that cost $0.45; after burning for four minutes it is 11.2 cm tall. You also have a red candle 8.9 cm tall that cost $0.40; after burning for ten minutes it is 7.5 cm tall. Analyze the burning rates with functions and graphs. If they are both lit at the same time, predict when (if ever) they will be the same height, and when each will burn down completely. Which costs less per minute to use?
Click here to see answer by ankor@dixie-net.com(22740)  |
Question 59000: Talia plans to make tallitot(prayer shawls) and matching kipot(prayer hats) from a bolt of material. The fabric she plans to use is 250 yards long. She will need 2 yards of material for each tallitot(prayer shawl) and 1/6 of a yard for each kipah(prayer hat). She also plans to put tzitzit(fringes) on the tallit and will need 1 yard of cord for each tallit. The kipot will not have any fringes. She has 100 yards of cord to use for the tzitzit.
1. Please help me find the two equations to use to solve for how many kipot and tallitot she can make from the supplies on hand.t=tallipot and k=kipot.
I know that you have to have yards+yards=yards but i am confused to were the 100yards of fringe cord comes into play. Thank you very much i needed it!
Click here to see answer by stanbon(75887) |
Question 59623: I submitted this problem earlier today but made a mistake. The correct problem is: Find the dimensions of a box whose volume is 196 cu. in., whose surface area is 280 sq. in., and whose LENGTH is twice its width.
I got 2 equations:
196=2W^2H (W is width and H is height)
280=4W^2+6WH
I solved the first equation for H and substituted it in the 2nd equation, ending up with:
4W^3-280W+588=0
I can't figure out where to go from here.
Click here to see answer by venugopalramana(3286) |
Question 60981: This is a two part question. Can anyone help me set these up. I seem to have issues with these slopes. Thanks!
Using point P(2,9) and Q (-3,3)
Find distance between P and Q.
Find the equation of the line passing through P and Q.
Thanks again!
Click here to see answer by joyofmath(189) |
Question 61902: Hi you guys, i need help with this question for sat or sunday, thank you very much.
Find the distance from the point Q(-3,-3,-4) to the line which passes through the point P(3,3,-4) and is parallel to the line whose equation is:
(x,y,z) = (-7,1,-2) + t(-1,-2,2).
Click here to see answer by venugopalramana(3286) |
Question 62053: Smith bicycled 45 miles going east from Durango, and Jones bicycled 70 miles. Jones averaged 5 miles per hour than Smith, and his trip took 1/2 hour longer than Smith's. How fast was each one traveling?
Click here to see answer by uma(370) |
Question 62609: Consider the linear transformation T : R3 -> R2 whose matrix
with respect to the standard bases is given by
2 1 0
0 2 -1
Now consider the bases:
f1= (2, 4, 0)
f2= (1, 0, 1)
f3= (0, 3, 0) of R3 and
g1= (1, 1)
g2= (1,−1) of R2
Compute the coordinate transformation matrices between the standard
bases and these bases and compute the matrix of T with respect to the new
bases.
Any help would be appreciated. Thank you!
Click here to see answer by venugopalramana(3286) |
Question 62451: Find the shortest distance between the two lines:
(x,y,z) = (2,-1,2) + t(-3,-2,-2)
(x,y,z) = (-3,4,1) + s(0,2,0)
Thanks sooo much!
Click here to see answer by venugopalramana(3286) |
Question 62805: Hi,my name is Natalia. I solved two problems, but I'm not sure that I did it right. I would really appreciate if you can check them.
Here are two given problem:
Consider a vector space V=Mat 3x3 of all 3x3 matrices
Q.: determine the dimension of V,find and verify a basis for it.
here is what i've got so far:
if the matrix is
/a b c/
/d e f/
/g h i/
then the basis for it is
/1 0 0/ /0 1 0/ /0 0 1/ /0 0 0/ /0 0 0/ /0 0 0/ /0 0 0/ /0 0 0/ /0 0 0/
/0 0 0/,/0 0 0/,/0 0 0/,/1 0 0/,/0 1 0/,/0 0 1/,/0 0 0/,/0 0 0/,/0 0 0/
/0 0 0/ /0 0 0/ /0 0 0/ /0 0 0/ /0 0 0/ /0 0 0/ /1 0 0/ /0 1 0/ /0 0 1/
So, i have 9 vectors v1, v2,...,v9 that are lineraly independent and span
therefore, dimV=9 if the matrix is symmetric dimV=6 and if the matrix is scew-symmetric dimV=9 Am I correct?
And the second problem:
A have a matrix A=
/1 2 3 /
/2 5 7 /
/3 7 10/
that lookes like A=
/1 0 1/
/0 1 1/
/0 0 0/ when row-reduced
I need to express a vector x=
/2 /
/-1/
/7 /
as a sum of a vector from the row space and a vector from nullspace
For nullspace I got (let's call it v so it will be easier to write an expression then)
/-1/
/-1/
/1 /
for row space (u and w respectively)
/1/ /0/
/0/ /1/
/1/ /1/
that gives me 3-D subspace
and the vector expression is:
x=2*v + 4*u + 1*w
did I solve it correct?
Thank you very much!
Click here to see answer by venugopalramana(3286) |
|
Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485, 1486..1530, 1531..1575, 1576..1620, 1621..1665, 1666..1710, 1711..1755, 1756..1800, 1801..1845, 1846..1890, 1891..1935, 1936..1980, 1981..2025, 2026..2070, 2071..2115, 2116..2160, 2161..2205, 2206..2250, 2251..2295, 2296..2340, 2341..2385, 2386..2430, 2431..2475, 2476..2520, 2521..2565, 2566..2610, 2611..2655, 2656..2700, 2701..2745, 2746..2790, 2791..2835, 2836..2880, 2881..2925, 2926..2970, 2971..3015, 3016..3060, 3061..3105, 3106..3150, 3151..3195, 3196..3240, 3241..3285, 3286..3330, 3331..3375, 3376..3420, 3421..3465, 3466..3510, 3511..3555, 3556..3600, 3601..3645, 3646..3690, 3691..3735, 3736..3780, 3781..3825, 3826..3870, 3871..3915, 3916..3960, 3961..4005, 4006..4050, 4051..4095, 4096..4140, 4141..4185, 4186..4230, 4231..4275, 4276..4320, 4321..4365, 4366..4410, 4411..4455, 4456..4500, 4501..4545, 4546..4590, 4591..4635, 4636..4680, 4681..4725, 4726..4770, 4771..4815, 4816..4860, 4861..4905, 4906..4950, 4951..4995, 4996..5040, 5041..5085, 5086..5130, 5131..5175, 5176..5220, 5221..5265, 5266..5310, 5311..5355, 5356..5400, 5401..5445, 5446..5490, 5491..5535, 5536..5580, 5581..5625, 5626..5670, 5671..5715, 5716..5760
|
