Question

Solve the following system of equations.

x + 4y + z = –10
3x – 3y + 6z = –21
x + 2y + 2z = –10

(1, –2, –3)

(–4, –1, –2)

(–3, –2, –3)

(2, –2, –4)

Answer 1

B? :/

Answer 2

@jim_thompson5910

Answer 3

It is indeed B.

Answer 4

\[\left[\begin{matrix}1 & 4& 1 & -10 \\ 3 & -3 & 6 & -21\\ 1&2&2&-10\end{matrix}\right]\]
Row 1: R_1
Row 2: R_2
Row 3: R_3

1. R_1: R_1 - R_3 = 0,2,-1,0
2. R_3: R_3 - R_1 = 1,0,3,-10
3. R_2: R_2 - 3R_3 = 0,-3,-3,9
4. R_2: R_2 / -3 = 0,1,1,-3
5. R_1: R_1 - 2R_2 = 0,0,-3,6
**6. R_1: R_1 / -3 = 0,0,1,-2
** 7. R_2: R_2 - R_1 = 0,1,0,-1
** 8. R_3: R_3 - 3R_1 = 1,0,0,-4
Therfore x_1 = -4, x_2 = -1, x_3 = -2