Questions on Algebra: Matrices, determinant, Cramer rule answered by real tutors!

Tutors Answer Your Questions about Matrices-and-determiminant (FREE)

Question 328638: Find the inverse of the matrix.
2 3
3 -5
Click here to see answer by Fombitz(13828)

Question 329422: I need some help in solving this problem. The current ina stream moves at a speed of 2 km/h. A boat travel 27 km upstream and 27 km downstream in a total of 17 hours. What is the speed of the boat in still water?
Click here to see answer by stanbon(57962)

Question 330377: Solve the following system of equations using the inverse matrix method.

Find x,y,z
Click here to see answer by Edwin McCravy(8999)

Question 330501: 2) Solve the following linear system using matrices:
2x-y+3z=-4
x-2y+z=-1
x-5y+2z=-3

Click here to see answer by Fombitz(13828)

Question 330776: How many negative real zeros does the function f(x) = x5 + x4 – x2 – x + 1 have?
Click here to see answer by Fombitz(13828)

Question 330981: Solve x^2-4x=1 by completing the square.
Click here to see answer by solver91311(17077)

Question 331362: i have a math problem that looks like four numbers inside these brackets that look like [ ] plus four more numbers in those brackets. how do i solve that?
Click here to see answer by Edwin McCravy(8999)

Question 331843: 9<-2.5a what the answer? and show you come up with the answer show work please.
Click here to see answer by rfer(12729)

Question 332233: Can someone show me how to use the elimination method to solve this problem. The solution says it is (4y+1,y) for any real numbers. I just don't kow how they go it. Thanks
2x-8y=2
3x-12y=3
Click here to see answer by jim_thompson5910(28708)

Question 332230: It says to use the elimination method for this problem but I don't understand what to do because it says the answers has not solution. Can someone please help. I am so confused.
2x+3y=15
8x+12y=40
Click here to see answer by Alan3354(31518)

Question 332650: Use the Gauss-Jordan Method to solve the system of equations.
x = 1 - y
2x = Z
2z = 2 - y
I am really confused by this totally and really have no idea where to start. Can someone help please.

Click here to see answer by solver91311(17077)

Question 332777: multiply both side of the equation by a common denominator to eliminate the
fractions. Then solve the system.

x/4+3y=31
2x-y/5=8
I have been struggling to try to solve this for over 4 days now and have had no luck. We are given the final answer which is (5,10) but I can not figurge out how they got to that. I need to show the work and solve the problem. Can someone please help me.

Click here to see answer by mananth(12270)

Question 332786: Multiply both side of the equation by a common denominator to eliminate the
fractions. Then solve the system.
x/5+3y=31
2x-y/5=8
I have been struggling to try to solve this for over 4 days now and have had no
luck. We are given the final answer which is (5,10) but I can not figurge out
how they got to that. I need to show the work and solve the problem. Can
someone please help me.
Click here to see answer by Earlsdon(6294)

Question 332776: I solve this by using elimination and show my work.

4x-3y=-1
x+2y=19
I need help plz. I have been trying to solve this for three days now.
Click here to see answer by Jstrasner(106)

Question 332827: evaluate the determinant 2 3
3 2
Click here to see answer by solver91311(17077)

Question 332774: I own a company that sells high-end computers; I made 2 orders from a vendor: the first one was for 1300 desktops and 400 laptops totaling $48,700. The second order was for 600 desktops and 200 laptops totaling $23,200. The receipts were not itemized. What is the cost of one desktop and one laptop?
I need to be able to show the work.
Click here to see answer by jrfrunner(365)

Question 333165: Solve by elimination:
-x+3y=6
x-9y=9
Click here to see answer by checkley77(12569)

Question 333163: Solve by elmination:
x-y=3
x+3y=3
Click here to see answer by nyc_function(2733)

Question 333420: Can you help please. I need to use elimination to solve this system. I have been struggling for a couple of days. I need to show my work. Thanks in advance.
x-y=3
x+3y=3
Click here to see answer by rfer(12729)

Question 334119: use the echelon method to solve the system of two equations in two unknowns.
x-3y=-4
-7x-2y=28
please show work
Click here to see answer by solver91311(17077)

Question 334121: Find the monthly house payment necessary to amortize the following loan.
In order to purchase a home, a family borrows $167,000 at 8.2% for 15 yr. What is their monthly payment? Round the answer to the nearest cent.
A)$1615.28 B)$1141.17 C)$11,751.63 D)$1865.85
please show work
Click here to see answer by rfer(12729)

Question 334799: Will someone please show me how to find determinant A by expanding by column 1,
Given Matrix A:
(1 3 4)
(2 -1 3)
(3 1 -2)
Any help would be great.
Thanks, -Nick.

Click here to see answer by Alan3354(31518)

Question 334985: If a+b=15, a+c=16, and b+c=11, how do you get a b and c on the calculator?
Click here to see answer by stanbon(57962)

Question 334985: If a+b=15, a+c=16, and b+c=11, how do you get a b and c on the calculator?
Click here to see answer by Edwin McCravy(8999)

Question 335600: 1. find the sum of the first 25 terms for 6, 11, 16, 21...
2. give the rule for 5, 10, 20, 40...
3.what is the 50th term of an=4n-3?
4. if r=3 and a1=6 what is the rule?
5. what is false about 7,14,28,56...
Click here to see answer by nyc_function(2733)

Question 335367: solve using matrices:
2x-y=6,
8x+2y=0
Click here to see answer by Fombitz(13828)

Question 335524: 3x+y+z=5
4x+5y-z=-8
10x+7y+z=2
Solve by Gauss-Jordan method
Click here to see answer by CharlesG2(828)

Question 336153: How do I solve this problem. I know it's done through matrices but I'm still very confused on the concept so explanation would be greatly appreciated.
3x-y+z= -9
2x+y-z= -1
x-y-z= -7
Click here to see answer by tinbar(128)

Question 335887: what is the determinant of the matrix
B= 6 6 2 1 4
3 7 3 6 5
3 0 6 3 0
7 6 4 2 -2
Click here to see answer by Fombitz(13828)

Question 336938: I need help in the matrix problem.
Click here to see answer by solver91311(17077)

Question 337293: what is the answer to the equation 6x+3=4x+11
Click here to see answer by stanbon(57962)

Question 337292: what is the answer to the equation 6x+3=4x+11
Click here to see answer by scott8148(6628)

Question 337486: what is tha answer for 3(a-b)/9+4/9b
Click here to see answer by Fombitz(13828)

Question 338743: i have difficulty in this question..help me!
find the quadratic polynomial whose graph goes through the points (-1,0), (0,1) and (2,21).
and the answr should be f(x)= __x^2+__x+__
Click here to see answer by Fombitz(13828)

Question 339458: Matrices subtraction B-CF

Click here to see answer by Edwin McCravy(8999)

Question 341372: 30=-5(6n+6)
Click here to see answer by rfer(12729)

Question 341500: Use determinants to determine the number of solutions for each of the following systems.Do Not solve the systems.
A)3x-y= -6
2x= 3y+2

B)3x-y=7
6x-2y=10

Click here to see answer by stanbon(57962)

Question 341598:
Evaluate the square of A and find x,y,z, not all zero, such that the matrix

xI+yA+zAA is the zero matrix.
Click here to see answer by Edwin McCravy(8999)

Question 343462: A dietitian wants a patient to have meal with 66 grams of protein, 94.5 grams of carbohydrates, and 910 milligrams of calcium. The meal is composed of chicken, corn, milk. Each serving of chicken has 30 grams of protein, 35 grams of carbs, and 200 milligrams of calcium. Each serving of corn has 3 grams of protein, 16 grams of carbs, and 10 milligrams of calcium. Each serving of milk has 9 grams of protein, 13 grams of carbs, and 300 milligrams of calcium. How many servings of each need to be given to the patient?
I got the problems set up like this:
chicken=x
corn=y
milk=z
30x+3y+9z=66
35x+16y+13z=94.5
200x+10y+300z=910
I am pretty sure I need to do matrices , but don't know how to break it down? Can you please help me?
Click here to see answer by Fombitz(13828)

Question 343616: 7x-4=31
Click here to see answer by rfer(12729)

Question 343596: Solve using elimination method
5x-2y=-4
3x-5y=6
Click here to see answer by Fombitz(13828)

Question 343991: Solve by the Gauss-Jordan elimination:
x+y+2z+t=1
x+2y+z+t=2
2x+y+z+t=4
x+y+z+2t=3
Click here to see answer by Edwin McCravy(8999)

Question 344039: the bean counter charges $9.00 per pound for kenya french roast coffee and $8.00 per pound for sumatran coffee. How much of each type should be used to make a 20-lb blend that sells for $8.40?
Click here to see answer by stanbon(57962)

Question 344118: the sum of three numbers is 41. the first is ten less than the third and the second is one less than twice the third. What are the three numbers?
Click here to see answer by rfer(12729)

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