y =( 1/2)x- 1(x & gt； =2)

y = 1-( 1/2)x(x & lt； 2) Point (x, y) above

Similarly, set b also consists of two dotted lines:

y =-x+b(x & gt； =0)

y = x+b(x & lt； Points below 0 (x, y)

If their intersection is not an empty set, b>= 1 will do.

(2) x+2y

So as long as b=9/2, the meaning of the problem can be satisfied.

Drawing pictures by yourself can help you understand.