3x+ 2y+ 7z=38

9x+ 6y+ 21z=114

0.6x+ 0.4y+ 1.4z=7.6

Select one:

a.{(x,y,z) |3x+ 2y+ 7z=38}

b.{(-1,-4,7})

c.{(1,4,-7)}

d.{ }