(3/5+7/8+12/25)*33 1/3=(120/200+175/200+96/200)*100/3=
=391/200*100/3=391/6=65 1/6
(10 1/2+9 1/4)*(10 1/2-9 1/4)=(10 3/4+9 1/4)*(10 3/4-9 1/4)=20*1 1/2=30
А)
72,28
39,59
-------
32,69
б)
99,705
54,864
-------
34,841
124-х-5=119-х
при х=51 119-51=68
при х=63 119-63=56