Question

Which of the following shows an inconsistent system of equations?

4x - 2y = 10 ; y = 2x - 5
3x + 2y = 1 ; 2x - 3y = 1
2x + y = 2 ; y = -2x - 2
3x + 4y = 5 ; 6x + 8y = 10

Answer 1

The third set is equivalent to

2x + y = 2
2x + y = -2

clearly inconsistent.