Question

solve the system

x - 2y + z =4
-x + 4y - 3z =2
2x + y + 10z=10

Answer 1

What math are you in because you can either put this in a matrix which is faster or you can write it all out by hand

Answer 2

Do you know matrices?

Answer 3

nope. i think it has to be the traditional way

Answer 4

Then you need to solve for each variable one at a time. Do you need help getting started?

Answer 5

@rshextall yes please! :)

Answer 6

Then lets start with the first equation and solve for x.

Answer 7

Just add 2y and subtract z from both sides of the equation
\[x-2y+2y+z-z=4+2y-z\]
\[x=4+2y-z\]

Answer 8

Do you see what happened there?

Answer 9

yup !

Answer 10

Then you need to plug it into one of the other equations and solve for either y or z

Answer 11

so plugging it into the 2nd equation mates it 2y-2z=6 ? then?

Answer 12

Right!!!

Answer 13

It takes a while but it's not to difficult, but its easy to make simple mistakes like forgetting a minus sign and stuff

Answer 14

then?

Answer 15

Then solve for either y or z

Answer 16

Then you have to both x and the other into the last equation and solve for the last variable

Answer 17

You can check your answer by plugging your answers for x, y, and z into the first equations. They should work for all 3 equations

Answer 18

Did you get it?

Answer 19

z=-1 y=2 x=9. yup i got it thanks!

Answer 20

@rshextall but can you show me how to do the matrix, it's in the next lesson of the book so i think i should learn it too.

Answer 21

You have to learn the rules of matrices. They're a bit more in depth than we can really get into on here. If you like I can help you with your homework with it when you get it