250- [35/100 • 250 +3/5 (250-30/100•250)] =
250- [35/10 • 25 +3/5 (250-3/1 • 25)] =
250- [7/2 • 25 +3/5 (250-3•25)] =
250- [175/2 +3/5 (250-75)] =
250-( 175/2 + 3/5 • 175)=
250-(175/2 +3/1 • 35)=
250-(175/2+ 105/1)=
250-(175/2+ 2•105/2)=
250-(175+210)/2=250- 385/2= 250- 192,5=57,5
