Question 9: This kind of question type often appears in high school (visual inspection of this Jiangsu? ), in fact, as long as you draw a picture, the key point is that the continuous representation of the intersection point (x=2) on R should also satisfy the subtraction function, so it is listed.

a-20

2a- 1>0

Solve a > 1

These two problems are common problems. If you are careful, you won't have any problems.