3.5÷x=1.2
3.5/x=1.2
1.2x=3.5
x=3.5/1.2
22.5*0.48+7.75*0.48
=48/100*(22.5+7.75)
=12/25*121/4
=363/25
2-6/13÷9/26-2/3
=2-6/13*26/9-2/3
=2-4/3-2/3
=0