First transformation.
Duadrilateral ABCD has vertices with such coordinates: 
- A(15,10);
 - B(15,20);
 - C(20,15);
 - D(20,5).
 
Apply a rotation by 90°counterclockwise around point A to this quadrilateral, then
- A(15,10)→A'(15,10);
 - B(15,20)→B'(5,10);
 - C(20,15)→C'(10,15);
 - D(20,5)→D'(20,15).
 
Second transformation.
1. A reflection across the y axis has a rule:
(x,y)→(-x,y).
Then
- A'(15,10)→A''(-15,10);
 - B'(5,10)→B''(-5,10);
 - C'(10,15)→C''(-10,15);
 - D'(20,15)→D''(-20,15).
 
2. A translation 20 units down has a rule:
(x,y)→(x,y-20).
Then
- A''(-15,10)→G(-15,-10);
 - B''(-5,10)→H(-5,-10);
 - C''(-10,15)→I(-10,-5);
 - D''(-20,15)→J(-20,-5).
 
Answer: first blank -B, second blank - B.