Question

X+y-z=1;8x+3y-6z=1;-4x-y+3z=1​

Answer 1

Answer:

x =2 , y =3, z = 4

Step-by-step explanation:

X+y-z=1 --------------------1

8x+3y-6z=1----------------2

-4x-y+3z=1-------------------3

solving equation 1&3

X + Y -Z = 1

-4X - Y +3Z =1

_______________

-3X + 2Z =2

________________

=》Z = (2 + 3X)

__________ -----------------4

2

solving equation 1 and 2 (to eliminate ×3 with equation 1 )

3X + 3Y - 3Z = 3

8X + 3Y - 6Z = 1

(-) (-) (+) (-)

________________

-5X + 3Z = 2--------------5

_________________

substitute equation 4 in 5

-5X + 3× (2 + 3X) = 2

2

=》 -5X + 6 + 9X = 2

_____

2

=》 -10X + 6 + 9X = 4

=》 - X = 4-6

=》 -X = -2

=》 X = 2 Sustitute x=2 in equation 4

=》Z = (2 + 3(2))

_______ -----------------4

2

=》 Z = 8/2 =》 Z = 4

substitute x= 2 and z= 4 in equation 1

2 + y- 4 = 1 =》 y= 3