Привидите дробь 4/7 к новому знаменателю 14; 28; 49; 70; 210

14 : 7 = 2 - доп.множ = (4*2)/(7*2) = 8/14
28 : 7 = 4 - доп.множ. = (4*4)/(7*4) = 16/28
49 : 7 = 7 - доп.множ. = (4*7)/(7*7) = 28/49
70 : 7 = 10 - доп.множ. = (4*10)/(7*10) = 40/70
210 : 7 = 30 - доп.множ. = (4*30)/(7*30) = 120/210

1) 4/7 к 14 =2×7
4×2/14=8/14 ;

2) 4/7 к 28=7×4
= 4×4/28=16/28;

3) 4/7 к 49=7×7
4×7/49=28/49;

4) 4/7 к 70=7×10
4×10/70=40/70;

5) 4/7 к 210=7×30
4×30=210=120/210