Question

X+2y+3z=7

2x+y+z=4

3x+3y+z=14

Answer 1

X +2y +3z = 7
2x +y +z = 4
3x +3y +z = 14

z = 14 -3y -3x

2x + y +14 -3y -3x = 7
-x -2y = -7
-x = -7 +2y
x = 7 -2y

7 -2y +2y +3(14 -3y -3x) = 7
42 -9y -9(7 -2y) = 0
-63 +18y -9y = -42
9y = 63 -42
y = 21/9
y = 7/3

x = 7 -2(7/3)
x = 7 -14/3
x = (21 -14)/3
x = 7/3

z = 14 -3(7/3) -3(7/3)
z = 14 -21/3 -21/3
z = 14 -42/3
z = (42 -42)/3
z = 0