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

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

Question 58568: use Cramer's rule to solve the given system
4x+5y=12
3x+y=-2
Click here to see answer by stanbon(75887)

Question 58567: solve the following system of equations using matrices
x-y+4z=6
2x+z=1
x+5y+z=-9
is it (0, 1, -2)??
Click here to see answer by funmath(2933)

Question 58565: perform the matrix row operations and write the new matrix
|2 -4 1 | 4 |
|-5 0 1 | -3 | -3R1+R2
|-1 5 -2 | -1 |
Click here to see answer by venugopalramana(3286)

Question 58564: use cramer's rule to solve the given system:
2x+4y=14
4x+3y=18

Click here to see answer by funmath(2933)

Question 58564: use cramer's rule to solve the given system:
2x+4y=14
4x+3y=18

Click here to see answer by charmedgurl013(1)

Question 58744: using x, y, z and w, for the variables, write the system of linear equations represented by the given augmented matrix:
9 1 0 8|6
-1 5 1 0|-12
7 0 0 3|-9
0 4 0 -4|8
Click here to see answer by checkley71(8403)

Question 58743: use Cramer's rule to solve the given system:
2x+2y=32
2x-3y=-3
is it 7,9?
Click here to see answer by checkley71(8403)

Question 58742: please write the system of linear equations represented by the augmented matrix:
[945|-2]
[509|4]
[850|2]
Click here to see answer by checkley71(8403)

Question 58741: write the determinant
-9-7
4 5
Click here to see answer by funmath(2933)

Question 60374: 8x+9y=1
-2x+6y=5 solve this matrix. I am the older sister, who hasnt done matrix stuff since high school. I am trying to remember how to solve this equation. can you please help. sorry i didnt try, i doont have a book or anything.
Click here to see answer by kayeith(17)

Question 60004: 3x-3y=3
-2x =0 what is x and y

Click here to see answer by kayeith(17)

Question 60558: I need to solve this equation:
(500-x)/y = 1.28
(470-x)/y = 0.25
Click here to see answer by jai_kos(139)

Question 60557: I need to solve this equation:
(500-x)/y = 1.28
(470-x)/y = 0.25
Click here to see answer by jai_kos(139)

Question 60688: x+3=0
x+y+z=1
3x-y-z=11
We must use the Gauss-Jordan elimination.
I have already tried the problem with others and i keep getting the same wrong answer. the book says the answer is (3,-1,-1).
I did this:
1 3 0 / 0
1 1 1 / 1
3 -1 -1 / 11
then i did multiplied -1 to the first row and added to the second row. then multiplied -3 to the first row and added the product to the third row which gave me
1 3 0 / 0
0 -2 1 / 1
0 -10 -1 / 11
i then multiplied -1/2 to the second row which gives me
1 3 0 / 0
0 1 -1/2 / -1/2
0 -10 -1 / 11
them i multiplied 10 to the second row and added the product to the third row and got
1 3 0 / 0
0 1 -1/2 / -1/2
0 0 -6 / 16
by multiplying -1/6 to the third row gave me
1 3 0 / 0
0 1 -1/2 / -1/2
0 0 1 / -16/6
then i multiplied 1/2 to row 3 and added it to row 2 giving me
1 3 0 / 0
0 1 0 / -4/3
0 0 -6 / -16/6
then by multiplying -3 to the row 2 and adding that to row 1 i got
1 0 0 / 4
0 1 0 / -4/3
0 0 1 / -16/6
this give me the answer (4,-4/3,-16/6) which is clearly wrong. Could you look over my steps to see what i did wrong please?

Click here to see answer by hayek(51)

Question 61310: Decompose into partial fractions (check your answers)[x^2 -10x +13]/[x^2 -5x +6)(x-1)]
Click here to see answer by venugopalramana(3286)

Question 61637: The local yogurt bar features a banana treat made up of 2lb of bananas, 3lb of topping , and 4lb of frozen yogurt. The cost of the banana treat is $19.00. One pound of topping costs $1 less than one pound of frozen yogurt, which costs as much as 1/2 pound of topping and 4 pounds of bananas. How much does one pound of each ingredient cost?
Click here to see answer by ptaylor(2198)

Question 61622: The local yogurtbar features a banana treat made up of 2lb of bananas, 3lb of topping, and 4lb of frozen yogurt. The cost of the banana treat is $19.00. One pound of topping cost $1 less than one pound of frozen yogurt, which costs as much as 1/2 pound of topping and 4 pound of bananas. How much does one pound of each ingredient cost?
Click here to see answer by ankor@dixie-net.com(22740)

Question 62816: Find real numbers a, b, and c such that the graph of the function ax^2 + bx + c contains the points (1,1), (2,4), and (-3,29).
Click here to see answer by venugopalramana(3286)

Question 62883: okay, i'm not very good at matrices...
[4 2]____[-6 0]
[5 1]*A= [-15 3]
(find matrix A)
please help i'll be very grateful!!
ps. sorry if it's confusing these are two 2x2 matrices ^^
Click here to see answer by stanbon(75887)

Question 62817: Solve the system of equations using matrices.
3x - 2y + z = -7
x + y - 2z = 12
3x + y - z = 10
Click here to see answer by venugopalramana(3286)

Question 63037: hello. I would like help on finding the inverse of a 3x3 matrix. my textbook does not explain how to find it.
thank you
Kyle
Click here to see answer by stanbon(75887)

Question 63045: i need lots of tutoring on this! im in algebra 2 and i dont get a thing! plz help!
Click here to see answer by stanbon(75887)

Question 63377: find the coefficent of x^5y^5 in the expansion of (2x+3y)^10
thank you
Click here to see answer by fomunearantess@yahoo.com(2)

Question 63494: You have $9,000 to invest in three Internet companies listed on the stock market. You expect the annual returns for companies A, B and C to be 10%, 9% and 6%, respectively. You want the combined investment in comapnies B and C to be twice that of company A. How much should you invest in each company to obtain an average return of 8%?
1.) Set up three equations.
2.) Solve using any of the differnt types of matrix equations, and state which method you are using.

** Please help me with this if you can, I have been trying for about an hour and a half now, and I am completley stumped!! THANK YOU!!
Click here to see answer by stanbon(75887)

Question 63502: Given the following system of three equations, write as an augmented matrix.
3x - 2y + z = 4
2x + y = 3
x + 2y - 3z = 5
Click here to see answer by Edwin McCravy(20054)

Question 63501: Perform the row operations on the given augmented matrix.
a.) R₂ = 3r₁ + r₂
b.) R₃ = -2r₁ + r₃
c.) R₃ = 4r₂ + r₃
1 2 -3 | 4
-3 -5 8 | -10
2 0 -1 | 4
Click here to see answer by Edwin McCravy(20054)

Question 63500: A company manufactures three types of wooden chairs; the Kitui, the Goa, and the Santa Fe. To make a Kitui chair requires one hour of cutting time, 1.5 hours of assembly time, and one hour of finishing time. A Goa chair requires 1.5 hours of cutting time, 2.5 hours for assembly, and 2 hours for finishing. The Santa Fe requires 1.5 hours of cutting, 3 hours of assembly, and 3 hours of finishing. If 40 hours of cutting time, 70 hours of assembly, and 58 hours of finishing time were used one week, how many of each type of chair were produced?
Click here to see answer by stanbon(75887)

Question 63463: 2x-y-z=-3
x-2y+3z=6
x+y+z=6
use matrices to solve thank you
Click here to see answer by ptaylor(2198)

Question 63397: using matrices 2x-y-z=-3
x-2y+3z=6
x+y+z=6
thank you
Click here to see answer by venugopalramana(3286)

Question 63926: It is common practice for supermarkets to charge same price per unit
Please help !
I had sumbitted this yesterday but havent go a response yet ...please help
Irrespective of the number of units that the customer buys. Fair supermarkets (FS) sells one of its |�catch cow � products for $ 1500 per unit. Using appropriate concept of calculus determine

o Revenue generated when 10000 units of the � catch cow � product are sold
o Additional revenue when between 500 and 15000 units if the � catch cow� product are sold

Click here to see answer by stanbon(75887)

Question 64070: A company manufactures three types of wooden chairs; the Kitui, the Goa, and the Santa Fe. To make a Kitui chair requires one hour of cutting time, 1.5 hours of assembly time, and one hour of finishing time. A Goa chair requires 1.5 hours of cutting time, 2.5 hours for assembly, and 2 hours for finishing.
The Santa Fe requires 1.5 hours of cutting, 3 hours of assembly, and 3 hours of finishing.If 41 hours of cutting time, 70 hours of assembly, and 58 hours of finishing time were used one week, how many of each type of chair were produced?

Click here to see answer by stanbon(75887)

Question 64185: I need help with making equations out of matrices with x and y?
Click here to see answer by venugopalramana(3286)

Question 64179: x - y + w = -4
-2x + y + z = 8
2x - 2y - z = -10
-2x + z + w = 5
Please solve this system of equations using the reduced row echelon form of the matrix.
Click here to see answer by venugopalramana(3286)

Question 64107: Solve the system if possible.
2x-4y+2z=11
x+3y-2z=-9
4x-2y+z=7
Click here to see answer by ankor@dixie-net.com(22740)

Question 64327: Solve the system of linear equations by using the matrices: [9,3,4][x1]=7
[4,3,4][x2]=8
[1,1,1][x3]=3
Thank you!
Click here to see answer by venugopalramana(3286)

Question 64626: I have tried for 2 days to solve this one! I have the answers, and they do solve the equations, so they are correct. However, I am unable to produce the answers using matrix transformations. Any step-by-step help would be appreciated.
-2r + 6s -3t + 3v = -5
4r - 3s + 2t -v = -3
-3r - 4s - 3t + 4v = -15
5r + 2s - 2t + 3v = -20
The solution is r,s,t,v = -2,1,3,-2 respectively.
Click here to see answer by venugopalramana(3286)

Question 64640: during a race a high performance sailboat traveled 54 miles with the wind in 3 hours. the return trip, against the wind, took 6 hours. find the rate of the boat in calm water and the rate of the wind
Click here to see answer by ptaylor(2198)

Question 65004: How do you raise a matrix equation by a negative number?
Click here to see answer by stanbon(75887)

Question 65225: I need super fast help!
Use Gaussian elimination to solve the system:
x-3z=-2
3x+y-2z=5
2x + 2y + z=4
After working through it, the numbers dont seem to fit. I have no idea what im doing wrong. I came up with 1 0 -3 -2
0 1 -5.5 -1
0 0 1 3.5
but when I plug the numbers in, they dont fit the equation. I dont know at what step I went wrong and my work is due tomorrow! Please help!
Click here to see answer by stanbon(75887)

Question 65283: If (5,6) IS ON A LINE WITH THE SLOPE OF 4/3, GIVE THE COORDINATES FOR ANOTHER POINT ON THE LINE.
Click here to see answer by ptaylor(2198)

Question 65300: What's the determinant of {6 0}?
{3 4}
Click here to see answer by funmath(2933)

Question 65299: What is an inverse?
Click here to see answer by checkley71(8403)

Question 65472: This is a word problem question that has to be solved using cramers rule
At a college basketball game, student tickets cost 12 dollars each, adult tickets cost 16 dollars each and childrens tickets cost 7 dollars each. Four times as many adult tickets as children tickets were sold, the total number of childrens tickets and adult tickets was half the number of student tickets. The total number of tickets sales was 33,043 dollars. How many of each type of ticket was sold?
Click here to see answer by Edwin McCravy(20054)

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