9.

Solve the following system of equations

3x - 2y + 4z = 20

-x + 5x + 12z = 73

x + 3y - 2z = 1

Select the appropriate response:

A) x = 4, y = 3, z = 5

B) x = 2, y = 3, z = 5

C) x = 5, y = 5, z = 5

D) x = 7, y = 8, z = 5

B) x = 2, y = 3 and z = 5.

Step-by-step explanation:

3x - 2y + 4z = 20 ... A

-x + 5y + 12z = 73 ... B

x + 3y - 2z = 1 ... C

Adding B and C:

8y + 10z = 74 ... E

Multiply equation B by - 3:

-3x - 9y + 6z = - 3

Add this equation to A:

-11y + 10z = 17

Subtract this equation fro E:

19y = 57

y = 3.

Substitute y = 3 in equation E:

8*3 + 10z = 74

10z = 50

z = 5.

Finally substitute y = 3 and z = 5 into equation C:

x + 3 (3) - 2 (5) = 1

x + 9 - 10 = 1

x = 1 + 1

x = 2.

B) x = 2, y = 3, z = 5

Step-by-step explanation:

3x - 2y + 4z = 20

3 (2) - 2 (3) + 4 (5) = 20

20 = 20

-x + 5y + 12z = 73

-2 + 5 (3) + 12 (5) = 73

73 = 73

x + 3y - 2z = 1

2 + 3 (3) - 2 (5) = 1

1 = 1