Question

x+2y+2z=3. 2x-2y-z=3. x-2z=-5​

Answer 1

Answer:

x = 1, y = -2, z = 3.

Step-by-step explanation:

x + 2y + 2z = 3      A

2x -2y - z = 3         B

x - 2z = -5              C

If we add equations A and B we eliminate y:

3x + z = 6       E

Multiply E by 2 :

6x + 2z = 12    F

Adding C and F we get:

7x = 7

x = 1.

Plug this into equaton C:

1 - 2z = -5

-2z =  -5 - 1 = -6

z = 3.

Now plugging x = 1 and z = 3 in equation A:

1 + 2y + 2(3) = 3

2y = 3 - 1 - 6 = -4

y = -2.