Raymond B. answered 24d
Math, microeconomics or criminal justice
a system of equations has no solution when they are inconsistent
for example x=1 and x=2 are an inconsistent system with no real solution
2y+z=1
2x+4y+az=0
x+3y-z=k
is more complicated.
3rd equation is same as 2x+6y -2x =2k
which is inconsistent with 2nd equation
when a=-2 and k=0
other values of a and k create inconsistencies