Could you please please check over these for me? ASAP 10 pts

If you were to use the substitution method to solve the following system, choose the new system of equations that would result if x was isolated in the second equation.
5x - 2y - z = 16
x + y + 4z = 6
3x + 2y + 6z = 16 (1 points)
A) -3y + 19z = -14
5y + 18z = -2
B) 7x + 7z = 28<-----
x - 2z = 4
C) -7y - 21z = -14
-y - 6z = -2
D) 21x - 7y = 70
33x - 10y = 112


If you were to use the elimination method to solve the following system, choose the new system of equations that would result after the variable z is eliminated in the first and second equations, then the second and third equations.
3x - 5y + 2z = 7
4x + 9y - z = 2
x - 3y + 3z = 7 (1 points)
A) 11x + 13y = 11<------
13x + 24y = 13
B) 11x + 13y = 11
3x - 5y = 7
C) x - 3y = 7
13x + 24y = 13
D) x - 3y = 7
3x - 5y = 7

Solve the following system of equations.
4x - 2y - z = -5
x - 3y + 2z = 3
3x + y - 2z = -5 (1 points)
A) (0, 1, 3)
B) (0, -1, 3)
C) (0, 1, -3) <----
D) (0, -1, -3)

Im just want to check to see if im right? ugh!

- 5x + 2y + z + 5(x + y + 4z) = - 16 + 5(6)
- 5x + 2y + z + 5x + 5y + 20z = - 16 + 30
7y + 21z = 14
y + 3z = 2

Answer: 7y + 21z = 14 OR option C. - 7y - 21z = - 14
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3x - 5y + 2z + 2(4x + 9y - z) = 7 + 2(2)
3x - 5y + 2z + 8x + 18y - 2z = 7 + 4
11x + 13y = 11

Answer: option A. 11x + 13y = 11
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3 equations combined—z:
- 4x + 2y + z + x - 3y + 2z + 3x + y - 2z = 5 + 3 - 5
z = 3

1st equation—y in terms of x, substitute z:
4x - 2y - 3 = - 5
2y = 4x + 2
y = 2x + 1

2nd equation—x, substitute y & z:
x - 3(2x + 1) + 2(3) = 3
x - 6x - 3 + 6 = 3
5x = 0
x = 0

1st equation—y, substitute x:
= 2(0) + 1
= 0 + 1
= 1

Answer: option A) (0, 1, 3)