Can you please check these for me. I just want to make sure I'm doing this right. Thanks.

1) Solve the following system of equations:

x + y = 6
y = 2x

answer: (2, 4)


2) Solve the following systems of equations:

2x - 3y = -13
y = 2x + 7

answer: (-2, 3)


3) Solve the following

x = 3y + 7
x = 2y - 1

answer: (-17, -8)


4) Solve

x + y = 6
x - y = -2

answer: (2, 4)


5) Solve

3x + 2y = 14
3x - 2y = 10

answer: (4, 1)


6) Solve

3x - 7y = 13
6x + 5y = 7

answer: (2, 1)



7) Solve

2x + 3y = -16
5x - 10y = 20

answer: {-20/7, -24/7}

8) Solve

5x = 6y + 40
2y = 8 - 3x

answer: {32/7, -20/7}


9) Solve
x - y + 3z = 8
3x + y = -2z = -2
2x + 4y + z = 0

answer: {1, -1, 2}


10) Solve

2x + 3y = 7z = 13
3x + 2y - 5z = -22
5x + 7y - 3z = -28

answer: (-1, -2, 3)


11) Solve

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

answer: (1, 1, 2)


12) Solve

x + 3y + 5z = 20
y - 4z = -16
3x - 2y + 9z = 36

answer: (0, 0, 4)


13) Solve

x + y = 4
x + z = 4
y + z = 4

answer: (2, 2, 2)


14) Solve
x - 3z = -5
2x - y + 2z = 16
7x - 3y - 5z = 19

answer: (4, -2, 3)

I double checked the first couple an they were right so you are doing the problems correctly.