Question 284406
X+Y+Z=22
X+Y=15
3X+Y+Z=37 
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X+Y+Z=22
X+Y=15
----------- Subtract
z = 7
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3X+Y+Z=37 
3x+y+7 = 37
3x+y = 30
x +y = 15
----------- Subtract
2x = 15
x = 15/2
y = 15/2
z = 7