the expression is,
y = -4x + 5
poitn a is
a(1,2)
put x = 1
y = -4(1) + 5
y = -4 + 5
y = 1
so it is not the satisfying the equation thus, this pair is not the solution
point b is
b(0,-4)
put x = 0
y = -4(0) + 5
y = 5
so it is not the satisfying the equation thus, this pair is not the solution
both the points are not the solution of the given equation