Question

Solve this system of equations using the inverse of a matrix.
-x + y = 8
4x + 3y = 12
x − 7y + z = 15

x = 4, y = 68, and z = 5.39
x = 68, y = 5.39, and z = 4
x = -1.76, y = 6.24, and z = 60.76
x = 6.24, y = -1.76, and z = 60.76
x = 72, y = -4, and z = 12.78

[Hint: AX = B and X = BA-1]

Answer 1

HI!!

Answer 2

i surely would not use that method!

Answer 3

hey

Answer 4

:)

Answer 5

\[-x + y = 8\\
4x + 3y = 12\] can be solved very easily

Answer 6

how do you solve?

Answer 7

multiply the first equation by \(-3\) and add

Answer 8

or multiply the first equation by \(4\) and add

Answer 9

either way

Answer 10

-3x+-3y=-24?

Answer 11

by \(-3\) you get \[3x-3y=-24\\
4x+3y=12\] add and the y's go bye bye

Answer 12

ok

Answer 13

once you have \(x\) and \(y\) plug them in to the third equation to find \(z\)

Answer 14

so 3x=-24

Answer 15

and 4x=12?

Answer 16

...

Answer 17

I am just going to take it as C