Question

Which system of equations has no solution?

A.
3
x
−
y
=
2

9
x
−
3
y
=
6

B.
9
x
−
6
y
=
30

x
−
2
y
=
6

C.
4
x
−
y
=
1

8
x
−
2
y
=
2

D.
4
x
−
y
=
−
5

4
x
−
y
=
−
3

Answer 1

D.

Both equations in D have identical left sides (4x − y) but different constants (−5 and −3), so they are parallel and inconsistent (no solution).