Question

Which system of equations below has no solution?

y = 4x + 5 and y = 4x – 5
y = 4x + 5 and 2y = 8x + 10
y = 4x + 5 and y = 1/4x + 5
y = 4x + 5 and y = 8x + 10

Answer 1

non but third

we can solve all of them because they are parallel but third isn't.

Answer 2

y = 4x + 5 and y = 4x - 5