а)5/7 и 1/2;
НСК(7,2)=7*2=14
5/7=(5*2)/(7*2)=10/14
1/2=(1*7)/(2*7)=7/14
б)7/20 и 1/15;
НСК(20,15)=60
7/20=(7*3)/(20*3)=21/20
1/15=(1*4)/(15*4)=4/60
в)3/26 и 5/39;
НСК(26,39)=78
3/26=(3*3)/(26*3)=9/78
5/39=(5*2)/(39*2)=10/78
г)8/11 и 5/8;
НСК(11,8)=88
8/11=(8*8)/(11*8)=64/88
5/8=(5*11)/(8*11)=55/88
д)7/13 и 2/11;
НСК(13,11)=143
7/13=(7*11)/(13*11)=77/143
2/11=(2*13)/(11*13)=26/143
е)3/22 и 2/33
НСК(22,33)=66
3/22=(3*3)/(22*3)=9/66
2/33=(2*2)/(33*2)=4/66