1 2/13*(3/7x-5/6)=2,5
15/13×(3/7х-5/6)=2 1/2 3/7х-5/6=5/2÷15/13 3/7х-5/6=5/2×13/15 3/7х-5/6=13/6 3/7х=13/6+5/6 3/7х=18/6 3/7х=3 х=3÷3/7 х=3×7/3 х=7