Question

Which of the following has a solution set of {x | x = 0}?
A. (x + 1 < -1) ∩ (x + 1 < 1)
B. (x + 1 ≤ 1) ∩ (x + 1 ≥ 1)
C. (x + 1 < 1) ∩ (x + 1 > 1)

Answer 1

it is B 
(x+1<1)this mark(x+1>1)

Answer 2

B, since by subtracting one from both sides of both equations, you get x <= 0 and x >= 0. That is only true for x = 0.