In the system below, use equation (1) with equation (2) to eliminate x. Then use equation (1) with equation (3) to eliminate x. x-y-2z=4 (1) - x+3y-z=8 (2) - 2x-y-4z=-1 (3) What is the new 2 * 2 system?

2y - 3z = 12 - 3y - 8z = 7

Step-by-step explanation:

(1) + (2) ⇒ (x - y - 2z) + (-x + 3y - z) = (4) + (8)

2y - 3z = 12

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2 (1) + (3) ⇒ 2 (x - y - 2z) + (-2x - y - 4z) = 2 (4) + (-1)

-3y - 8z = 7

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The reduced system of equations is ...

2y - 3z = 12 - 3y - 8z = 7

2y - 3z = 12.

-3y - 8z = 7.

Step-by-step explanation:

x - y - 2z = 4 (1)

-x + 3y - z = 8 (2)

-2x - y - 4z = - 1 (3)

Adding (1) + (2):

2y - 3z = 12.

2 * (1) + (3) gives:

-3y - 8z = 7.