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

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

Question 610284: Hello, my name is steve and i would like you to help me solve the Equation
7x+3y=21 by cramers rule if you would please thank you.
5x-4y=9
Click here to see answer by jim_thompson5910(35256)

Question 610491: After simplifying the matrix operation below, what does a32 equal?

5 12 12
19 7 16
5 16 7

+

8 6 5
14 3 10
20 9 19

Click here to see answer by jim_thompson5910(35256)

Question 610495: After simplifying the matrix operation below, what does a21 equal?
4 � (7)
(8)

Click here to see answer by jim_thompson5910(35256)

Question 610756: IT WOULD BE MUCH APPRECIATED IF I GOT HELP ON THESE 3 QUESTIONS I JUST SIMPLY DO NOT GET. PLEASE HELP ME. THANK YOU IN ADVANCE.
Click here to see answer by richwmiller(17219)

Question 610864: Let U = {q, r, s, t, u, v, w, x, y, z}
A = {q, s, u, w, y}
B = {q, s, y, z}
C = {v, w, x, y, z}.
Determine whether the set is well defined. The set of rivers that flow south to north

Click here to see answer by jim_thompson5910(35256)

Question 611552: What is the vertex of the parabola defined by---

Click here to see answer by richwmiller(17219)

Question 611625: 2 -3 2 1 4
1 2 3 4 5
2 0 -1 5 4
4 2 3 1 0
5 4 3 2 1
i want the detetminant of it

Click here to see answer by solver91311(24713)

Question 611601: simplify using cramer's rule:-
x-y=1
x+z=-6
x+y-2z=3
Click here to see answer by lynnlo(4176)

Question 611741: {2x-y=5
{3x+2y=-3
Need some help with cramers rule. Really stuck
Click here to see answer by solver91311(24713)

Question 612416: how to find the adjoint of a 3 by 3 matrix
Click here to see answer by ewatrrr(24785)

Question 612685: solve using cramer's rule:
4x-3y=-7
3x-9y=15
x=?, y=?
i put these equations in the augmented matrix form, but i was stuck on how to actually solve the equation. i thought that you were only able to solve cramers rule if you are given a square matrix.
can you please help me solve this equation?
Click here to see answer by Alan3354(69443)

Question 612687: A is a 3x3 matrix
A= [a, 3, 4]
[a, -3, 8]
[8, 4, a]
find all values of |A|=0.
Click here to see answer by stanbon(75887)

Question 613276: What is the determinant?
|5 7|
|3 8|
This is altogether but I couldn't make a straight line that was long enough
Click here to see answer by Alan3354(69443)

Question 613276: What is the determinant?
|5 7|
|3 8|
This is altogether but I couldn't make a straight line that was long enough
Click here to see answer by brittanylynn(1)

Question 613276: What is the determinant?
|5 7|
|3 8|
This is altogether but I couldn't make a straight line that was long enough
Click here to see answer by smaraya(8)

Question 614100: x^2-5x-36=0
Click here to see answer by solver91311(24713)

Question 615967: We're trying to help our soon with his math homework but we're totally stuck one this problem:
A store has a sale on almonds, pecans and pistachios. One lb of almonds, one lb of pecans and one lb of pistachios cost $12. Two lbs of almonds and three lbs of pecans cost $16. Three lbs of pecans and two lbs pistachios cost $24. Find the price of each kind of nut.

Thank you in advance for any help.
Click here to see answer by scott8148(6628)

Question 616252: I am havig difficulty determining the value of a determinant when there are fractions. Is there a short, easy way for me to evaluate? For example:
|3/4 3/4|
|1/16 -1/8|
I know the following:
(3/4)(-1/8)-(1/16)(3/4) = -3/32-3/64 = -9/64

what I cant explain is the numberator. Where is the -9 coming from? Please help!
Click here to see answer by dragonwalker(73)

Question 616567: If [x y z]B= [l m n o p], then the order of the matrix B is?

Click here to see answer by jsmallt9(3758)

Question 617378: Find the value of | -7 12|
| 4 -11|
Click here to see answer by jim_thompson5910(35256)

Question 618394: The Family Arts Center charges $22 for adults, $17 for senior citizens, and $6 for children under 12 for their live performances on Sunday afternoon. This past Sunday, the paid revenue was $13086 for 899 tickets sold. There were 47 more children than adults. How many children attended?
Click here to see answer by ewatrrr(24785)

Question 619643: Use Cramer rule to solve.
x + y + z = 12
x - y = 2
x - z = 4
Click here to see answer by ewatrrr(24785)

Question 619641: Use cramer rule to solve ..
x + y + z =12
x - y = 2
x - z = 4
Click here to see answer by ewatrrr(24785)

Question 619615: I want general solution for 6th degree polynomial.

Thank You.
Click here to see answer by ewatrrr(24785)

Question 620073: Please help find the value of the determinant.
-2 5 4
3 -2 1
1 6 -3
Thanks!
Click here to see answer by Alan3354(69443)

Question 620085: Solve the system of equations by using the inverse of the coefficient matrix.
-x-2y=8
3x+4y=24
also written as: x=x1 and y=x2
Please help!
thanks!
Click here to see answer by ewatrrr(24785)

Question 620164: Matrix: A= [5,2,1_7,6,3_1,0,2] B=[1,4,0_2,-1,2]
Find AB if possible. If i'm on the right track AB is not possible because it is a 3x3 times a 2x3...
It also asks for:
1. Find BA if possible, if not explain
For this i ended up with [33,26,13_5,-2,3] but I am not confident in my answer
2. Find 3A-4B if possible

Any help would be greatly appreciated. Thanks

Click here to see answer by ewatrrr(24785)

Question 620491: Help find the maximum or minimum value of the objective function, subject to the constraints graphed in this feasible region.
z = x + 6y + 9 Find minimum.
Click here to see answer by richard1234(7193)

Question 620728: if x/3y=4/7 and z/5y=2/21, then x/z=?
Click here to see answer by Maths68(1474)

Question 620730: Respected Sir/Madam,
Using Matrics Method solved the following equation
x-y+z=4
x-2y-2z=9
2x+y+3z=1
I want to know the value of x,y,z,
plz solved it and mailed me on this id
rajnisharma005@rediffmail.com
I shall be thankful to u for this
Rajni

Click here to see answer by lynnlo(4176)

Question 620071: Solve the system using the inverse method.
x + 2y + 3z = -2
x + y + z = -7
-x + y + 2z = -10
Click here to see answer by Edwin McCravy(20054)

Question 622203: Solve the system of equations using matrices
9Z+7Y= -3X
x+3Z=2-2Y
X+4Y-2+Z=0

Please Help
Thank You
Click here to see answer by lynnlo(4176)

Question 622429: You have worked a system down to the following augmented matrix. What can be said of the solution?

1 0 1 5
0 1 2 11
0 0 0 0

Click here to see answer by matineesuxxx(27)

Question 622428: You have worked a system down to the following augmented matrix. What can be said of the solution?

1 0 1 5
0 1 3 13
0 0 0 7

Click here to see answer by matineesuxxx(27)

Question 622427: You have the following matrix, and perform the following 3 row operations. What is the resultant matrix after performing these 3 row operations?
�R1 + R2  R2
2R1 + R3  R3
-4R2 + R3  R3

1 0 0 10
1 1 3 5
-2 2 0 4

Click here to see answer by Edwin McCravy(20054)

Question 622973: Cant figure this out.
perform the indicated operations and simplify Let A =matrix[3,-4_-2,5] Let B= matrix[5,-2,8_1,0,-3] and C=matrix[7,-9,0_3,-5,1_-1,6,2] Find AB+BC
Thanks ahead for the help.
Click here to see answer by mykasha(37)

Question 624836: Use the determinant to find the area of the triangle with the following vertices:
(-3,1)
(1,-3)
(2,3)
I know the area should be positive, but I'm still confused.
Click here to see answer by Alan3354(69443)

Question 625234: use cramer's rule to solve the system x-2y=-9, 3x+y=1
Click here to see answer by oscargut(2103)

Question 624927: how do i solve using inverse matrix method? x+2y-z=10 -2x+3y+z=6 3x-2y+2z=19
Click here to see answer by jsmallt9(3758)

Question 626268: Using the matrices find a general solution
2x-y+3z=5
-x+4y+4z=-1
if you could show how you did this I would really appreciate it. ty
Click here to see answer by Edwin McCravy(20054)

Question 626265: the first two rows of hte following matrix are already in trianular form. Finish the job by performing Gaussian elimination on row 3. What are the contents of row 3 after you have done so?
[1 6 -2 0]
0 -3 1 5]
[2 0 3 9]
if you could show how you did this I would really appreciate it. ty
Click here to see answer by saliiim8(6)

Question 626896: Find the inverse of the matrix if it exists.
A=
[3,-1,0]
[4,1,0]
[0,0,4]
A^-1=
Click here to see answer by ewatrrr(24785)

Question 626892: Find the inverse of the matrix if it exists.
A=
[2,-1,0]
[2,1,0]
[0,0,1]
A^-1=
Click here to see answer by ewatrrr(24785)

Question 626891: Find the determinant of the matrix.
A=
[6,3,-6]
[0,6,1]
[-3,4,0]
|A|=
Click here to see answer by ewatrrr(24785)

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