выполните сложение 3/7+1/28 +11/35 5/8+1/6+7/12 13/30 +2/45+1/9 3/11 +9/22+455 5/21+8/15+1/7 1/24+11/30+5/12

3/7 + 1/28+11/35=
=(3×20 + 5×1+4×11)/140=109/140
$$$$$$/$
5/8+1/6+7/12=(5×3+1×4+7×2)/24=33/24=11/8==1 3/8
$$$$$$$$
13/30+2/45+1/9=
=(13×3+2×2+10×1)/90=53/90
$$$$$$$$//$
3/11+9/22+4/55=
=(3×10+9×5+4×2)/110=83/110
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