Question

2x + 4y + z = 3 x − 2y − 3z = 4 x + y − z = −1

Answer 1

A) 2x + 4y + z = 3
B) x − 2y − 3z = 4
C) x + y − z = −1

Multiplying B & C by -1

B) -x + 2y + 3z = -4
C) -x - y + z = +1 Then adding to A
A) 2x + 4y + z = 3
5y + 5z = 0
So basically z = -y

A) 2x + 4y -y = 3
B) x − 2y + 3y = 4
C) x + y +y = −1

A) 2x + 3y = 3

Multiplyig B by -2
B) -2x -2y= -8
C) x + 2y = −1 Adding B&C
-x = -9
x = 9


A) 2*9 + 4y + z = 3
A) 4y + z = -15
B) 9 − 2y − 3z = 4
B) − 2y − 3z = -5

A) 4y + z = -15
B) − 2y − 3z = -5
Multiplying A by 3
A) 12y + 3z = -45
B) − 2y − 3z = -5 Then adding A & B
10y = -50
y = -5

C) x + y − z = −1
C) 9 -5 − z = −1
C)5  =z

So x = 9
y= -5
z = 5

Wow!!!!!!!!!!!!