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Tutors Answer Your Questions about Matrices-and-determiminant (FREE)
Question 241047: The sum of 3 numbers is 26. The second number is three times the first while the third number is four more than the first. What are the three numbers?
I just need help setting it up. I can use Cramer's rule well enough, I'm just not sure what to put into it to solve it.
Click here to see answer by jsmallt9(594)   |
Question 239300: I can't get Cramer's Rule to work for Y. It's OK for X and Z.
the matrix is:
1X + 3Y -1Z = 1
-2X -6Y + 1Z = -3
3X + 5Y -2Z = 4
The Determinate is 2.
X = 2, Y = 1, Z = 1 using Cramer's Rule, but this doesn't check
Using RREF, the solution is 2,0,1 which works.
When I take the determinate of Y in Cramer's rule, it is not 0 which it has to be to make Y=0.
what am I doing wrong?
could it be that Cramer's Rule doesn't work some times?
Thanks
Photonjohn
Click here to see answer by stanbon(26297) |
Question 237084: I'm trying to help my friend who is in Algebra 2 with her homework. I took Algebra 2 last year, and we seem to have skipped over lesson 5.7, Curve Fitting With Quadratic Models.
First and foremost, how would I write a system of equations represented by a 2 by 2 matrix.
I don't want the answer, I just want to know how to solve it.
So I will use different numbers.
The first row consists of 1 and 2
the second row is 3 and 4.
After that, there's a 1 by 2 matrix where row 1 consists of x and row 2 consists of y and then it equals a 1 by 2 matrix.
Click here to see answer by stanbon(26297) |
Question 230768: Using inverse matrix, solve the following problem:
A high school math department purchased brand A calculators
for $80 each and brand B calculators for $95 each. It purchased
a total of 20 calculators at a total cost of $1780. How many brand A
and brand B calculators did the department purchase?
Click here to see answer by rfer(2688) |
Question 229703: solve the system
x+y+z=-1
x-y+3z=-17
2x+y+z=-2
Solve the system
x-y+2z=7
2x+z=4
x+5y+z=9
Solve the system
3x+4y=-2
x=-2y
Solve the system
3x+4y=40
x-2y=0
Solve the system
x-y+z=6
x+y+z=2
x+y-z=0
Solve the system
y-3z=-12
-2x+y+2z=5
2x+3z=7
Click here to see answer by solver91311(5072)  |
Question 229023: Hi all, I asked this question recently but havnt been given a responce yet. Any help would be greatly appreciated.
I need to Solve the following system of equations by using Gaussian elimination. I also need to include the row operation used next to each row.
2x - y + 3z = 24
2y - z = 14
2x - 5y + 7z = 6
Thanks, -Nick.
Click here to see answer by stanbon(26297) |
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