If 4x+y+z=80, 2x-y-z=400,3x+y-z = 20 for integers of x,y and z, find x =?  Choose the correct choice from the following choices:
A) 10 B) 20 C) 15 D) 26 E) 18
4x+y+z = 80----------1)   2x-y-z = 40-------------2)   3x+y-z = 20 ------------3)   from 1) and 2)   6x = 120   x = 20   Answer is 20
<result>B</result>
If 4x+y+z=80, 2x-y-z=400,3x+y-z = 20 for integers of x,y and z, find x =?