Question

Hello! I'm having a really hard time solving this by Elimination and could really use some help ​

Answer 1

Answer:

x= 3, y=0, z= 1

Step-by-step explanation:

Let's label the 3 given equations first.

2x +3y +4z= 10 -----(1)

3x +2y -4z= 5 -----(2)

x +4y +2z= 5 -----(3)

(1) +(2):

This is to eliminate the z term.

2x +3y +4z +3x +2y -4z= 10 +5

5x +5y= 15

Divide by 5 on both sides:

x +y= 3 -----(4)

(3) ×2:

2x +8y +4z= 10 -----(5)

(2) +(5):

This is to eliminate z term.

3x +2y -4z + 2x +8y +4z= 5 +10

5x +10y= 15

Divide by 5 throughout.

x +2y= 3 -----(6)

(6) -(4):

x +2y -(x +y)= 3 -3

x +2y -x -y= 0

y= 0

subst. y=0 into (4):

x +0= 3

x= 3

subst. x=3, y=0 into (3):

3 +4(0) +2z= 5

3 +2z= 5

2z= 5 -3

2z= 2

z= 2÷2

z= 1