5/18×4×9/10=4×5/10×9/18 =4×1/2×1/2=1(1/4+2/9)×3.6=1/4×3.6+2/9×3.6=0.9+0.8=1.719×4/9=76/9
5/10=2;4/2=2; 18=2*9; 于是最后剩下2*2*9*9=4*81=324;(9+8)/36 x3.6=1.519X4/9=(2+1/9)X4=8+4/9