What is half minus four quarters plus four fifths? If you can calculate simply, you need to calculate simply! You need to write a formula

What is half minus four quarters plus four fifths? If you can calculate simply, you need to calculate simply! You need to write a formula

1/2-4/25+4/5
=1/2-4/25+20/25
=1/2+16/25
=25/50+32/50
=57/50