f÷7+25 = 900-(300-48×5)×9
f÷7+25 = 900-(300-240)×9
f÷7+25= 900-60×9
f÷7+25 = 900-540
f÷7+25 = 360
f÷7 = 360-25
f÷7 = 335
f = 335×7
f = 2 345
Raspuns: f = 2 345