Question

Solve the system of linear equations and check any solution algebraically.

x + y + z = 2
-x + 3y + 2z = 8
4x + y = 4

Answer 1

do you know how to use the elimination method?

probably, what we can do is to eliminate z variable first using the 1st and 2nd equation
then use the resulting equation apply another elimination method to solve for the variable x or y ^_^

so first, what can you do to the 1st and 2nd equation to eliminate z?

Answer 2

So could we multiply the 1st equation by 2 and then subtract it from the 2nd equasion?

Answer 3

yes exactly :)

Answer 4

i'm trying to solve it...

just tell me what equation you'll get after you applied what you said and let's compare it to mine, sounds good?

Answer 5

ok, so after multiplying and subtracting you would get

x + y + z = 2
3x - y = 8
4x + y = 4

right?

Answer 6

wait, you should do what you said:

\(\color{blue}{\text{Originally Posted by}}\) @alyssajobug
So could we multiply the 1st equation by 2 and then subtract it from the 2nd equasion?
\(\color{blue}{\text{End of Quote}}\)

multiply 1st equation by 2 :

so it will be 2x+2y+2z=2

then subtract this by 2nd equation

Answer 7

you should end up with one equation

(leave equation 3 for now)

Answer 8

So

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

?