Answer:
D
Step-by-step explanation:
The augmented matrix for the system of three equaitons is

Multiply the first row by 5, the second row by -3 and add these two rows:

Subtract the third row from the second:

Divide the third row by 6:

Now multiply the third equation by 26 and add it to the second row:

You get the system of three equations:

From the third equation

Substitute z=2 into the second equation:

Now substitute z=2 and y=5 into the first equation:

The solution is (1,5,2)