here is a math trick i.e,45-45=45.how is that explain me

9 + 8 + 7 + 6 + 5 + 4 + 3 + 2 + 1 = 45

Write 45 like :

987654321

1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = 45

Write 45 like :

123456789

987654321 - 123456789 = 864197532

8 + 6 + 4 + 1 + 9 + 7 + 5 + 3 + 2 = 45

987654321 [ 45 ] - 123456789 [ 45 ] = 864197532 [ 45 ]