4+5+8/11+7/11=9+15/11=9+1и4/11=10и4/11
3/11<7/11
7/9>2/3(6/9)
7/18>7/24(28/72>21/72)
3/8<2/5(15/40<16/40)
2.2/5;3/4;4/3(24/60;45/60;80/60)
3.1;1/5;1/6;1/9(1;18/90;15/9010/90)
4.Например,6/41.
17х -8х - 52 = 2711
17х - 8х = 2711 + 52
9х = 2763
х = 2763/9
х = 307
1см,6см,8см,9см,1дм,67см,8дм,9дм,1м,25дм.