Question

NEED HELP WITH MATRIXES!!?!?!??! please i will fan and medal if you help

Answer 1

http://prntscr.com/3krrkk here is first question i typed them all out

Answer 2

@jim_thompson5910 i saw you helping some other people with algebra 2 could u help me plz?

Answer 3

when they want the dimensions of the matrix, they just want to know the number of rows and columns

how many rows does this matrix have? how many columns?

you report the answer as m x n

m = # of rows
n = # of columns

Answer 4

so this would be -8? http://prntscr.com/3krukw

Answer 5

\(\Large b_{43}\) is the element in matrix B that is in row4, column3

Answer 6

not row3,column4

Answer 7

-11?

Answer 8

better

Answer 9

and how do you do this? http://prntscr.com/3krvls (i have alot of these)

Answer 10

I'll help with 2 more

Answer 11

ok ty i have so many and my teacher never tought us this stuff

Answer 12

to find B-A, you just subtract the corresponding elements

make sure to do it in the order b - a

b is from matrix B
a is from matrix A

Answer 13

for example, in row1,column1

b = 4
a = 3

b-a = 4-3 = 1

So in the answer matrix, and in row1 column1, the value is 1

Answer 14

so this? http://prntscr.com/3krwe3

Answer 15

oh wow, I mixed up A and B lol, sry about that

Answer 16

a = 4
b = 3

b - a = 3 - 4 = -1

that goes in row1,column1

Answer 17

do the same for the rest

Answer 18

http://prntscr.com/3krxru so this?

Answer 19

correct

Answer 20

Which expression gives the x-coordinate of the solution of the system?
http://prntscr.com/3kryda

Answer 21

I'm not sure what they mean by "expression"

Usually they ask for a specific number

Answer 22

http://prntscr.com/3krz8o here are the options

Answer 23

oh cramers rule

Answer 24

are you familiar with that rule?

Answer 25

yes i am, i mean i learned about it lil.....

Answer 26

do you know how to find determinants?

Answer 27

yes

Answer 28

wait how do you find more than 1

Answer 29

first set up the matrix of the coefficients drawn from the left side

Answer 30

i got 63 as the determinent

Answer 31

is that correct?

Answer 32

what is the original matrix

Answer 33

. http://prntscr.com/3ks2zl

Answer 34

this looks like a completely different problem

Answer 35

yea srry wrong screen shot

Answer 36

here is the right one http://prntscr.com/3ks3g7

Answer 37

turn that into a matrix though (the left side)

Answer 38

it isnt a matrix though here is the whole question: http://prntscr.com/3ks44d

Answer 39

you have to turn that left side into a matrix first

then you take the determinant of that matrix

Answer 40

how do you do that?

Answer 41

here's one page that explains (using an example)

http://www.coolmath.com/algebra/14-determinants-cramers-rule/04-cramers-rule-3x3-01.htm

Answer 42

ok and then what?

Answer 43

do you understand what's going on in that page?

Answer 44

-7 is the determinat right?

Answer 45

hopefully you see how to get that, but yeah it is

Answer 46

ok i dont get the Dx

Answer 47

and the Dy Dz

Answer 48

so which one is right http://prntscr.com/3ks87z

Answer 49

to find Dx, you first start off with your original matrix

then you replace the first column with 3, 16, 7

these values are the values found on the right hand side

then you take the determinant of that new matrix

Answer 50

i thought it was the 2nd one.... but im havnig second thoughts

Answer 51

hint: the solution for x is

x = Dx/D

D is the determinant of the original matrix
Dx is the determinant of the new matrix

Answer 52

41?

Answer 53

41 is what?

Answer 54

41 is Dx -7 is D

Answer 55

oh notice in your answer choices they don't have you evaluate Dx fully

Answer 56

it's like they evaluated halfway

Answer 57

so which one is correct?

Answer 58

i have to sumbit this in like an hour, and i have more to do could we pick up the a pace a lil?