Question

(1)3x+4y=15 2y-z=2 x+2z=9 (2) x+y+z=8 2x+3y-z=6 3x-y+z=8 (3)

Answer 1

3x+4y=15

2y-z=2

x+2z=9

y=(2+z)/2

x=9-2z

3(9-2z)+4+2z=15

z=4 y=3 x=1

x+y+z=8 (1)

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

3x-y+z=8 (3)

(1)+(2) 3x+4y=14

(1)-(3) -2x+2y=0

x=y

x=2 y=2 z=4

2x+y+z=16 (1)

3x+2y+4z=44 (2)

x+3y+5z=52

6x+3y+3z=48

x-2z=-12

-5x+2z=4

-4x=-8

x=2 z=7 y=5