SIMPLE........... u need to remove the bad quality because of which your brother is unhappy. i.e. of not working hard.
Work hard, revise everything being explained in the class, read chapters thoroughly, practice maths and bring really very good marks in your tests, FAs, exams and see the result , your brother will definitely be happy with u.
Just u need to do is HARD WORD and need PATIENCE..
HOPE IT HELPED......