Question

Use the substitution method to solve the following system of equations.

x + 2y - z = 2
3x + y - 2z = -15
3x + 4y - 3z = -2
Choose one answer.
A. (7, -4, -1)
B. (-7, -4, 1)
C. (7, -4, 1)
D. (-7, 4, -1)

Answer 1

start substituting son

Answer 2

Help? I'm giving medals

Answer 3

oh gosh medals.

Answer 4

start it first, ill tell you where you go wrong

Answer 5

x + 2y - z = 2
x = -2y + z + 2

3x + y - 2z = -15
3(-2y + z + 2) + y - 2z = -15
-6y + 3z + 6 + y - 2z = -15
-5y + z = -15 - 6
-5y + z = - 21
z = 5y - 21

3x + 4y - 3z = -2
3(-2y + z + 2) + 4y - 3z = -2
-6y + 3z + 6 + 4y - 3z = -2
-2y = -2 - 6
-2y = -8
y = 4

z = 5y - 21
z = 5(4) - 21
z = 20 - 21
z = -1

x = -2y + z + 2
x = -2(4) + (-1) + 2
x = -8 -1 + 2
x = -9 + 2
x = -7