4.28-1.75+2.72-3.25=(4.28+2.75)-(1.75+3.25)=7-5=2
=(4.28+2.72)-(1.75+3.25)=7-5=2
4.28-1.75+2.72-3.25=(4.28+2.72)-(1.75+3.25)=7-5=2
=(4.28+2.72)-(1.75+3.25) =7-5 =2