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Solve the system 6x -2y+z= -2 2x+ 3y – 3z =11 x+ 6y=31
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Solve the system 6x -2y+z= -2 2x+ 3y – 3z =11 x+ 6y=31
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Mathematics
5 years
2021-08-13T13:58:07+00:00
2021-08-13T13:58:07+00:00 1 Answers
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Answers ( )
Answer:
x = 1
y = 5
z = 2
Step-by-step explanation:
System of equations:
6x – 2y + z = -2
2x + 3y – 3z = 11
x + 6y = 31
Isolate one variable in any of the equations:
x + 6y = 31
x = 31 – 6y
Plug in this value for x in another equation:
6(31 – 6y) – 2y + z = -2
186 – 36y – 2y + z = -2
186 – 38y + z = -2
-38y + z = -188
z = -188 + 38y
Plug in these values in the remaining equation:
2(31 – 6y) + 3y – 3(-188 + 38y) = 11
62 – 12y + 3y + 564 – 114y = 11
626 – 12y + 3y – 114y = 11
626 – 9y – 114y = 11
626 – 123y = 11
-123y = -615
y = 5
Plug in value of y into our other answers to solve for x and z:
x = 31 – 6(5)
x = 31 – 30
x = 1
z = -188 + 38(5)
z = -188 + 190
z = 2
Check your work:
6x – 2y + z = -2
6(1) – 2(5) + 2 = -2
6 – 10 + 2 = -2
-4 + 2 = -2
-2 = -2
Correct!
*Note there are several ways to solve for these types of problems. I used substitution*