(1/4+2/9)Ⅹ36=1/4X36十2/9X36(运用乘法分配律)=9+8=17
(1/4+2/9)×36=36×1/4+36×2/9=9+8=17 (1/4-2/9)×36=36×1/4-36×2/9=9-8=1 运用乘法分配律简便