Question

Algebra II Question. Please help ASAP. I need x,y and z. Thank you in advance! (This is elimination)
4x+y+3z=0
2x-2y-z=10
3x-2y+2z=11

Answer 1

well the most obvious is to eliminate y

so equation 1 times 2 + equation 2

8x + 2y + 6z = 0
2x - 2y - z = 10
--------------
10x + 5z = 10 divide each term by 5 and you get

2x + z = 2 call it equation (4)


then

2 times equation 1 + equation 3

8x + 2y + 6z = 0
3x - 2y + 2z = 11
-----------------
11x + 8z = 11 equation (5)


so you are now solving 2 equations in 2 unknowns

2x + z = 2 equation 4
11x + 8z = 11 equation 5

so equation 1 times 8 and subtract equation 5 will eliminate z

16x + 8z = 16
- 11x + 8z = 10
----------------
5x = 5

so x = 1

you can now go and use substitution to find y and z.

hope it helps

Answer 2

I don't know how to find y and z. This is so confusing for me

Answer 3

@campbell_st

Answer 4

well take equation 4 and substitute x =1 to find the value of z

when you get z

go to any of the initial equations and subsitute x = 1, z = your answer to find y

Answer 5

would z =0? @campbell_st

Answer 6

thats correct now y

Answer 7

Where am I supposed to plug in z? @campbell_st

Answer 8

use any of the initial equations you are given, substitute x = 1, z = 0 to find y.

choose which ever you feel comfortable with.

Answer 9

y=-4? @campbell_st

Answer 10

yes it is well done

Answer 11

I put that in and it told me I was wrong? @campbell_st

Answer 12

Nevermind I got it! I wrote it wrong! Thank you for your help! :) @campbell_st