0.8÷(4/5×1.25)÷(0.64-1/25)+1.2×0.5÷4/5
=0.8÷（4/5x5/4）÷（0.64-0.04）+0.6÷0.8
=0.8÷1÷0.6+3/4
=4/3+3/4
=16/12+9/12
=25/12