Answer:
(3,0,0)
Explanation:
3x + 5y + z = 9 --------------(I)
-4y - z = 0 -------------------(II)
z = -4y
2x + 3y - 4z = 6 (III)
Substitute z = -4y in equation (I) and (III)
3x +5y - 4y = 9
3x + y = 9 -----------------------(a)
2x + 3y - 4*(-4y) = 6
2x + 3y + 16y = 6
2x + 19y = 6 -------------------(b)
Multiply equation (a) by (-19) and then add. So, y will be eliminated and we can get the value of x
(a)*(-19) -57x - 19y = -171
(b) 2x + 19y = 6
-55x = -165
x = -165/-55
x = 3
Plugin x = 3 in equation (a)
3*3 + y = 9
9 + y = 9
y = 9 - 9
y = 0
Plug in y = 0 in equation (II)
-4*0 - z = 0
z = 0