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

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

Question 138809: I need some help with this problem please help! Find the sum, if possible.This is from a homework sheet.

Click here to see answer by Edwin McCravy(8879)

Question 138847: PROBLEM:
GIVEN THE FUNCTION DEFINED BY: f(x)=x^2-6x+12
A) IDENTIFY THE VERTEX OF THE PARABOLA.
B)DOES THIS PARABOLA OPEN UP OR DOWN?
C)DOES THE VERTEX REPRESENT THE MAXIMUM OR MINIMUM POINT OF THE FUNCTION?
D)WHAT IS THE MAXIMUM OF MINIMUM VALUE OF THE FUNCTION f?
E) WHAT IS THE AXIS OF SYMMETRY FOR THIS PARABOLA?
*** IN THIS PROBLEM I HAVE NO UNDERSTANDING OF ANY OF THIS.. I TRIED LOOKING IN THE BOOK FOR A SOLUTION,BUT STILL NO LUCK.. PLEASE HELP???!!
THANKS, lj23kfuller@yahoo.com

Click here to see answer by stanbon(57214)

Question 138931: PROBLEM:
A) WRITE THE FUNCTION IN THE FORM f(x)=a(x-h)^2+k BY COMPLETING THE SQUARE.
B) THEN IDENTIFY THE VERTEX. p(x)= -5x^2-10x-13
PLEASE HELP!! I'M JUST REALLY NOT UNDERSTANDING THIS WHOLE COMPLETE THE SQUARE THING, IT JUST ALL SEEMS SO FORIEGN?? THANKS
lj23kfuller@yahoo.com
Click here to see answer by solver91311(16868)

Question 140710: SOLVE USEING THE QUADRATIC FORMUALA
x^2= 3x
NOW I KNOW THE QUADRATIC FORMULA AND ALL BUT THIS ONE JUST SEEMS MORE DIFFICULT BECAUSE I DON'T KNOW HOW TO FIGURE OUT THE "a" AND "c" I THINK, TO PULG IT IN... I'M SURE THIS IS SO EASY BUT I'M MAKING IT VERY HARD... PLEASE HELP... THANKS SO MUCH.. :) :) :)
Click here to see answer by scott8148(6628)

Question 140707: SOLVE BY FACTORING:
x^2-5=4x
I'M VERY CONFUSED BECAUSE THIS IS REVIEWING QUESTIONS AND I CAN'T FIGURE THIS PROBLEM OUT PLEASE HELP??
Click here to see answer by jojo14344(1512)

Question 140626: Find the determinant.
4 -4 10
-1 1 -2
-2 -4 -3
Click here to see answer by Fombitz(13828)

Question 140724: WORD PROBLEMS:
282 PEOPLE ATTENED A RECENT PERFORMANCE OF CINDERELLA. ADULT TICKETS SOLD FOR $5 AND CHILDREN'S TICKETS SOLD FOR $3. FIND THE NUMBER OF ADULTS AND THE NUMBER OF CHILDREN THAT ATTENDED THE PLAY IF THE TOTAL REVENUE WAS $1046.
Click here to see answer by Fombitz(13828)

Question 140728: SOLVE BY COMPETING THE SQUARE:
x^2-6x+12=0
PLEASE HELP... I KNOW HOW TO USE THE QUADRATIC FORMULA... BUT I DO NOT KNOW HOW TO DO THE COMPLETING THE SQUARE...
Click here to see answer by checkley77(12569)

Question 140708: SOLVE USING THE SQUARE ROOT PROPERTY:
-2(x-2)^2= -6
HERE I'M CONFUSED ON WHAT ALL TO SQUARE??? DO I SQUARE EVERTHING ON THE RIGHT OR WHAT PLEASE HELP AS SOON AS YOU CAN... TAHNKS
Click here to see answer by checkley77(12569)

Question 140921: Find inverse of
a b c d
-b a -d c
-c d a -b
-d -c b a
If this is too difficult could you tell me how i go about finding the adjacent of a 4x4 matrix please. Thankyou
Click here to see answer by stanbon(57214)

Question 141192: I am having difficulty with augmented matrices. I need and would appreciate any help with this problem: Using the augmented matrices to solve the following 2X2 systems of equations. Final answer must be given in matrix form.
Problem to solve: -5x + 7y =9
x + 10y = 21
Click here to see answer by stanbon(57214)

Question 141427: 5a + 12b = 120
30a + 8b = 800
a> =0
b> =0
Click here to see answer by checkley77(12569)

Question 141622: Use augmented matrices to solve the following 2x2 systmes of equations. Show all work, final answers must be given in matrix form.
x+5y=11
2x+10y=25
Click here to see answer by nabla(475)

Question 141799: I am in desparate need of assistance with augmented matrix. I need to solve the following situation: A group of students decides to sell pizzas to help raise money for their senior class trip. They sold pepperoni for $12, sausage for $10, and cheese for $8. At the end of their sales the class sold a total of 600 pizzas and made $5900. The students sold 175 more cheese pizzas than sausage pizzas. Set up a system of three equations and three unknowns, use an augmented matrix to solve. Identify the three unknowns. Write a separate equation representing each of the first three sentences. Determine the augmented matrix that represents the three equations and solve for the matrix.
And finally,how many of each type of pizza were sold?
If any one can assistance I would appreciate the help.

Click here to see answer by stanbon(57214)

Question 142041: I am quite confused when it comes to the augmented matrix. I have been working on this problm for four hours and have gotten even more confused. Any assistance with this problem would be greatly appreciated.
A company’s employees are working to create a new energy bar. They would like the two key ingredients to be peanut butter and oats, and they want to make sure they have enough carbohydrates and protein in the bar to supply the athlete. They want a total of 31 carbohydrates and 23 grams of protein to make the bar sufficient. Using the following table, create a system of two equations and two unknowns to find how many tablespoons of each ingredient the bar will need. Solve the system of equations using matrices. I need to process the following by utilizing the table below. I need to write an equation for the total amount of carbohydrates. Write an equation for the total amount of protein.Determine the augmented matrix that represents the equations from A and B. Solve for the matrix and determine how many tablespoons of each will there need to be for the new energy bar?

Grams of Nutrients per tablespoon

Peanut Butter with 2 grams of Carbohydrates and 6 grams of protein
Oats with 5 grams of Carbohydrates and 1 grams of protein
Click here to see answer by stanbon(57214)

Question 143429: Determine the augmented matrix:p+s+c=600; 12p+10s+8c=5900; 0-s+c=175
Solve for the matrix and please show all work.
Click here to see answer by Edwin McCravy(8879)

Question 145141: I would really appreciate some help on a few questions please.These are on the cramers rule 3 x 3:
1)3x + y + 2z = 3
x - 5y - z = 0
2x + 3y + 2z = 0
2)x - 3y + z = 7
x + y - 3z = -9
x + y + z = 3
Thank you for your time and patients LJ
Click here to see answer by stanbon(57214)

Question 145151: Could someone please tell me if I'm right on these two Cramer rule problems?
1) 2x + 5y = 3
x + 4y = 2
I got(2/3,1/3)
2)x + 2y = 4
3x - 2y = -12
I got(-8,6)
Thank you in advance for helping me.
Sincerely, Elle J
Click here to see answer by scott8148(6628)

Question 145139: Could someone please help me with a few problems on cramer's rule? I want to know if I'm doing it right.Thank you so much in advance.
1)2x + 5y = 3
x + 4y = 2
2)x + 2y = 4
3x - 2y = -12
Click here to see answer by nerdybill(6948)

Question 145164: Could someone tell me if I got this problem right? It's worded,evaluate each determinant.I know that there is suppose to be the straight lines on each side, but I don't know how to do that on the computer.
1) 6 -7
5 8 I got 83 for the answer
Click here to see answer by nerdybill(6948)

Question 145190: I was wondering if someone could tell me if I got this problem right.
3x + y + 2z = 3
x - 5y - z = 0
2x + 3y + 2z = 0
I got as a final answer: -21, -12, 39
Thank you in advance for all the help you have given me. Elle J
Click here to see answer by vleith(2825)

Question 145192: Could someone help me with a few system of equations problems please? These ones are to be solved by the graphing method,and I have to show how I got them when I take the test in the future,So if you could show me step by step that would be great.
1) -x + y = -1
x + y = 3

2) 3x + y = -6
x + y = -4
Click here to see answer by jim_thompson5910(28476)

Question 145189: I was wondering if someone could tell me if I got these determinant problems right.
1) 0 4
1 5

2)5 3 -2
-1 1 6
2 4 1

3)-5 8 2
-6 0 3
7 -1 -4
1)-4 2)-88 3)-27
Click here to see answer by nerdybill(6948)

Question 145165: Could someone tell me if I got these determinant problems right?
1) 0 4
3) -5 8 2
-6 0 3
7 -1 -4 = -27
1 5 = -4

2) 5 3 -2
-1 1 6
2 4 1 = -88
Click here to see answer by Alan3354(30955)

Question 145163: hello
im a student in high school sturggling with matrices
x= 0 1 2 3 4.....
y= 1 2 4 7 11 ...........
using the matrices , how would i find
the equation using the MATRICES! ?>?>>
please help me
i will appreciate it so much
i have a test tomorrow :(
please help

Click here to see answer by Edwin McCravy(8879)

Question 145533: Use the Gauss-Jordan method to solve each system of equations.
3x-6y+3z=11
2x-y+z=-9
5x-5y+2z=18
I know how to change it into matrix form but then what?
Click here to see answer by jim_thompson5910(28476)

Question 146084: Please solve the system of equation for all variables using a matrix.

My solution
2 1=-4
1 3=9
r2 reverse r1
1 3=9
2 1=-4
r2* -2
1 3=9
0 -1=-6
r2* 2
1 3=9
0 1=-12
r2*-3+r1
1 0=-6
0 1=-12
x= -6 and y= -12
Please help I'm trying to get these steps, but i think my mutiplcation is off somewhere. Thanks in advance.
Click here to see answer by stanbon(57214)

Question 146083: Please solve the systems of equations for all variables using a matrix.

My Final answer Was X=5,y=1,z=-5 but when mutiplied it does not give me the numbers above. So I started working it again and got loss on the 4th step. Thanks in advance
I did this 1 2 0=7
0 3 1=5
2 0-3=-5,
r1 x-2+ r3
1 2 0=7
0 3 1=5
0-4-3=-19
r2 Divide by 3
1 2 0=7
0 1 3=0.6
0-4-3=-19
r3 divide by 4
1 2 0=7
0 1 3=0.6
0 0 1=-15
then i loss it and don't know which way to go

Click here to see answer by stanbon(57214)

Question 146652: Solve the following linear system for x using Cramer's rule show work
x+2y-3z=-22
2s-6y+8z=74
-x-2y+4z=29
Click here to see answer by Alan3354(30955)

Question 146738: Can you help me solve this Using augmented matrices to solve the following 2 x 2 systems of equations. Show all work.
1. 3x + 4y = 11
x + 3y = 2

Click here to see answer by nerdybill(6948)

Question 146844: I understand how to get determinants using numbers, i just do not know how to write the anwser using yhe constants, can you help me understand this part?please.

solve foy x and y using determinants: ax+by=c
dx-ey=f
Click here to see answer by stanbon(57214)

Question 147013: 7x - 2y = 4
5y + 3x = 10
thank you
Click here to see answer by jim_thompson5910(28476)

Question 146908: I need to sove using Cramer's Rule:
x+3y=21
10x-5y=0
Click here to see answer by nerdybill(6948)

Question 146909: Help with Cramer's Rule of:
x+2y+3z=14
5x-3y+z=2
3x+4y-2z=5
Click here to see answer by stanbon(57214)

Question 147888: given f(x)=2x^2-3x+4
where A=matrix (-1 2)
(0 3)
find P(A)
Click here to see answer by stanbon(57214)

Question 148324: how do you slove a 3 by 3 matrices that deals with cofactors?
My problem:

Click here to see answer by Edwin McCravy(8879)

Question 148512: Find the product of these two matrices
[1 4 1] }
[3 -6 2] }[4 1] the first two are part of the same matrix
Click here to see answer by jim_thompson5910(28476)

Question 148619: I need help solving this problem using the Gaussian Elimination method step by step please!
4x+3y+2z=6
-2x-y+5z=5
x+2y-3z=3
thank you in advance!

Click here to see answer by Fombitz(13828)

Question 150001: I need some help on this equation. I need to use the gauss-jordan method solving by matrices. thanks
4x - 2y = 3
-2x + 3y = 1
Click here to see answer by ntnk(54)

Question 150364: Use the Gauss - Jordan method to solve the system of equations.
3x +12y =-12
-6x-17y = 3

Here is my work, but i'm not sure if it's correct
[3 12 |-12] 1/3 R1
[-6 -17 |3] 2 R1 + R2

Turns to [1 4 |-4] -4 R2+R1
[0 7 |-27] 1/7

Turns to [1 0 |11 3/7] X= 11 3/7
[0 1 | -3 6/7] Y= -3 6/7

answer {(11 3/7, -3 6/7)}
Click here to see answer by stanbon(57214)

Question 150363: Use the Gauss - Jordan method to solve the system of equations.
3x +12y =-12
-6x-17y = 3

Here is my work, but i'm not sure if it's correct
[3 12 |-12] 1/3 R1
[-6 -17 |3] 2 R1 + R2

Turns to [1 4 |-4] -4 R2+R1
[0 7 |-27] 1/7

Turns to [1 0 |11 3/7] X= 11 3/7
[0 1 | -3 6/7] Y= -3 6/7

answer {(11 3/7, -3 6/7)}
Click here to see answer by mgmoeab(28)

Question 150808: Problem: A survey of 615 teenagers found that 44% of the boys and 35% of the girls would like to be taller. Altogether, 231 teenagers in the survey wished they were taller.
(1) Set up a system of equations to model this scenario.
(2) Use determinants and Cramer’s rule to determine how many boys and how many girls were in the survey.
(3) Answer the question in (2) by using inverse matrices.
(4) Compare the two methods. When might one method be better than another method for solving a system?

Click here to see answer by mangopeeler07(462)

Question 150947: problem- If 20 lbs of rice and 10 lbs of potatoes cost $16.20, and 30 lbs of rice and 12 lbs of potatoes cost $23.04, how much will 10 lbs of rice and 50 lbs of potatoes cost?
solve the linear system using the echelon method
Click here to see answer by checkley77(12569)

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