(7/20-2/15+1/6)÷2又1/5×4又4/5
=【7/(4×5)-1/(3×5)+1/6】×5/11×24/5
=(7/4×1/5-2/3×1/5+1/6)×24/11
=【1/5(7/4-2/3)+1/6】×24/11
=(1/5×13/12+1/6)×24/11
=1/5×13/12×24/11+1/6×24/11
=26/55+4/11
=26/55+20/55
=46/55
(7/20-2/15+1/6)÷2又1/5×4又4/5
=【7/(4×5)-1/(3×5)+1/6】×5/11×24/5
=(7/4×1/5-2/3×1/5+1/6)×24/11
=【1/5(7/4-2/3)+1/6】×24/11
=(1/5×13/12+1/6)×24/11
=1/5×13/12×24/11+1/6×24/11
=26/55+4/11
=26/55+20/55
=46/55