1. x*(1-7/9-1/12)=5/36*1/4
x*(36/36-28/36-3/36)=(5*1)/(36*4)
x*((36-28-3)/36)=5/144
x*(5/36)=5/144
x=5/144:5/36
x+5/144*36/5
x=(5*36)/(144*5)=180/720=1/4
2. 2целое5/11x+3целое6/11x=1цел2/9
x*((2+3)+(5/11+6/11))=11/9
x*(5+11/11)=11/9
6x=11/9
x=11/9:6
x=(11*1)/(9*6)=11/54