Question

determine the products [ 2 -3 5] [1 -1 1]
[ 3 2-4] [1 -2 -2]
[1 1-2 ] [2 1 3] and use it to solve the system of equations :
x-y =4,x-2y-2z=9,2x+y+3z=1.

Answer 1

How does the product help you solve for the systems? Just set up the augment matrix of the system of equations

Answer 2

what is augment matrix? @Romero

Answer 3

[1 -1 1 4 ]
[1 -2 -2 9 ]
[2 1 3 1 ]

Answer 4

x-y+ z =4
x-2y-2z=9
2x+y+3z=1

Answer 5

but i have never solved any matrix of 4 terms.
so i can't use this one. :(

Answer 6

Have you ever solved using row reduction?

Answer 7

yes.

Answer 8

Same concept is applied in larger matrices. It doesn't change....you just have to work a little longer.

Answer 9

can you please solve this one.here please

Answer 10

It's all the same

[1 -1 1 4 ]
[1 -2 -2 9 ]
[2 1 3 1 ]

[1 -1 1 4 ]
[0 -1 -3 5 ] Here I subtracted the first row to row two and row three
[0 3 1 -7] since the third had a 2 in it's first column I subtract 2*(row 1)

[1 -1 1 4 ]
[0 1 3 -5 ] I multiplied row two by -1
[0 3 1 -7]

[1 0 4 -1 ]
[0 1 3 -5 ] I subtract 3*(row 2) to row three
[0 0 -8 8 ] and added row two to row 1

Answer 11

Can you do the rest? Does this look familiar to you now?

Answer 12

do i need to solve the equations now? @Romero

Answer 13

What type of math are you taking?

Answer 14

@Romero .
i am using algebraic mathematics