(3 1/8+1 3/4)х=2 1/6
(3 1/8+1 3/4)х=2 1/6 (3 1/8+7/4)х=2 1/6 (25/8+14/8)х=2 1/6 39/8х=13/6 х=13/6*8/39 х=1/6*8/3=1/3*4/3=4/9