X+y+6z, если x-4y=5 , 15y+18z=33

Question

X+y+6z, если x-4y=5 , 15y+18z=33

Answer 1

X - 4Y = 5 
X = 4Y + 5 
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15Y + 18Z = 33 
18Z = 33 - 15Y 
6Z = 11 - 5Y 
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X + Y + 6Z = 4Y + 5 + Y + 11 - 5Y = 5Y - 5Y + 16 = 16 
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X + Y + 6Z = 16