Please explain solution to game theory.One simultaneous, other sequential

two players two strategies: expend and no change

PLAYER B Expand NO CHANGE PLAYER EXP 50, 20 85, 25 A NO CHANGE 70, 40 95, 30 A B Expand 50 20 Expand B 83 25 A CHANGE 70 40 NO EXP CHANGE B NO 95. 30