Question

Solve each system help

Answer 1

3x + 5z = -4
-2x + y - 3x = 9
-x - 2y + 9z = 0

Answer 2

@amistre64

Answer 3

@jim_thompson5910

Answer 4

well, there are 3 basic textbook approaches

substitution, elimination, and matrixes

Answer 5

i know how to do it on a calculator but not by hand and that's on the non cal part on my test

Answer 6

substitution seems the most intuitive; either method will be a bit labor intensive regardless.

which method are you most comfortable with by hand?

Answer 7

if we can reduce it to 2 equations in 2 unknowns; you should have no problem with it right?

Answer 8

yes

Answer 9

I know I can like multiply 2 equations to eliminate one variable and then substitute but I don't know how

Answer 10

3x + 0y + 5z = -4
-2x + y - 3z = 9
- x - 2y + 9z = 0


use one of the equations as a base .... use it to work out the other 2. spose I use eq1 to modify the other 2

3x + 0y + 5z = -4 ; times 2/3 to get rid of xs
-2x + y - 3z = 9

2x + 0y +10/3z = -4/3
-2x + y - 3 z = 9
----------------------
y +1/3 z = 23/3

3y + 1z = 23




and for the other one

3x + 0y + 5z = -4
- x - 2y + 9z = 0 ; *3 to eliminate the xs


3x + 0y + 5z = -4
-3x - 6y + 54z = 0
-------------------
-6y +59z = -4

Answer 11

now we are down to 2 eqs in 2 unknowns

3y + 1z = 23
-6y +59z = -4

if i did it right of course

Answer 12

yeah, i think my mathing needs to be double ckecked but thats the idea of it

Answer 13

ok well thanks for the help

Answer 14

BRB

Answer 15

3x + 0y + 5z = -4 ; times 2/3 to get rid of xs
-2x + y - 3z = 9

2x + 0y +10/3z = -4/3 <--- -8/3 ***********
-2x + y - 3 z = 9
----------------------
y +1/3 z = 19/3

3y + 1z = 19

Answer 16

3x + 0y + 5z = -4
- x - 2y + 9z = 0 ; *3 to eliminate the xs


3x + 0y + 5z = -4
-3x - 6y + 27z = 0 9*3 = 27, had a 6 on the brain
-------------------
-6y +32z = -4

Answer 17

3y + 1z = 19
-6y +32z = -4

6y + 2z = 38
-6y +32z = -4
--------------
34z = 34

thats better