1. 18/27 = 2/3, 0,5=1/2, 3/4=15/20
2. 15/х=3/20; х=100
3. 3/16; 5/24;
4. 1/8=0,125; 1/4=0,25; 2/5=0,4; 1/2=0,5
5. 3/4=0,75; 7/20=0,35; 3/15=0,2
6. 3/20
7. 4/9; 7/15
8. 3/8
9. 2/3+2/7=14/21+6/21=20/21
5/10-7/15=15/30-14/30=1/30
5/7+1/28=20/28+1/28=21/28=3/4
10.3 7/12+1 5/6-2 2/3=43/12+11/6-8/3=43/12+22/12-32/12=33/12=2 9/12=2 3/4