А3.
=3 9/48-1 28/48=2 57/48-1 28/48=
=1 27/48
а4.
=1 10/24+2 15/24=3 25/24=4 1/24
а5.
12×2 5/6=12×17/6=34
3 4/7÷1 1/14=25/7÷15/14=
=25/7×14/15=10/3=3 1/3
34-3 1/3=30 2/3
90дм+80дм=17м=170дм
360см-70см=29дм=290см
7^1,8:7^0,2=7^(1,8-0,2)=7^1,6
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a^m:a^n=a^(m-n)