（9.3×9/16-7.3×9/16)÷9／4
=9/16×（9.3-7.3）÷9/4
=9/16×2×4/9
=1/2
1／5×37％＋0．63×20％＋43
=1/5×（37%+0.63）+43
=1/5×1+43
=0.2+43
=43.2