4)(5,4-2 1/3):7 2/3; 5) (2 1/3+0,25)*0,12; 6)(7,6-4 3/4):1,9;

4. (5,4-2¹/₃):7²/₃=0,4.
1) 5,4-2¹/₃=5²/₅=2¹/₃=27/5-7/3=(27*3-7*5)/15=(81-35)/15=46/15
2) 46/15:7²/₃=46/15:23/3=46*3/(15*23)=2/5=0,4.
5) (2¹/₃+0,25)*0,12=(7/3+1/4)*0,12=((7*4+1*3)/12)*0,12=((28+3)12)*-0,12-
(31/12)*(12/100)=31*12/(12*100)=31/100=0,31.
3) (7,6-4³/₄):1,9=(76/10-19/4):1,9=(38/5-19/4):1,9=((38*4-19*5)/20):1,9=
=((152-95)/20):1,9=57/20:19/10=57*10/(20*19)=3/2=1,5.