(7/25×2/3+2/3×18/25)÷2/3 = 2/3(7/25+18/25)×3/2= 25/25 = 1 (11/14-5/7+5/28)×28 = (22/28-20/28+5/28)×28= 7/28 × 28 = 7 2/7×(1÷3/4-3/4÷1)=2/7 ×(1×4/3-3/4×1)=2/7 × 7/12 = 1/6