Question

What is the solution to the system of equations?

Answer 1

2x + y - z = 7
-x - 2y - 2z = -9 --- (multiply by 2)
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2x + y - z = 7
-2x - 4y - 4z = -18 (result of multiplying by 2)
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-3y - 5z = - 11

-x - 2y - 2z = -9
x + 3y - 3z = 6
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y - 5z = - 3

-3y - 5z = -11
y - 5z = -3 --- (multiply by -1)
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-3y - 5z = -11
-y + 5z = 3 (result of multiplying by -1)
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-4y = -8
y = 2

-3y - 5z = -11
-3(2) - 5z = -11
-6 - 5z = -11
-5z = -11 + 6
-5z = -5
z = 1

x + 3y - 3z = 6
x + 3(2) - 3(1) = 6
x + 6 - 3 = 6
x + 3 = 6
x = 6 - 3
x = 3

so we have : x = 3, y = 2, and z = 1

Answer 2

WHOA! you didnt have to do it all you couldve walked me through or told me what to do! but Thank You ANyway !