How can i simplify [ (15:2) + 34]-8.5+26

[ (15/2) + 34]-8.5+26

1st take care of whats inside of the ():

[ (7.5) + 34]-8.5+26

add up whats inside of the []:

[41.5]-8.5+26

41.5-8.5+26

now add everything up:

41.5-8.5+26

33+26

=59

your answer is 59.