1)0,75a-b:8 1/11pria=11:1/3i b=8,9;

0,75a-b:8 1/11=0,75a-b:89/11=0,75a-b.11/89=0,75-11b/89a=11:1/3=11.3=33, b=8,90,75.33-11.8,9/89=24,75-11.1/10=24,75-1,1=23,65