( x-7/4)×2/3=0 ; 12 (x-13/10×5/6)=0; 9 (x-7/2×4/7)=0
1. ( x-7/4)×2/3=0
( x-7/4)×2/3=0
x-7/4=0
x=7/4
вообще не понятно