因为98×48=49×2×48=96×49,所以原式等于96×49-49×29-49×10运用乘法分配律逆运算有49×(96-49-10)=1813
9+98×48-49×29-49×10=9+49×(2×48-29-10)=9+49×(96-39)=9+49×57=2802
98×48-49x29-49×10=(49+49)x48-49x(29+10)=49x(48+48)-49×39=49×(48+48-39)=49x57=2793
98×89 =(100-2)×89 =8900-2×89 =8900-2×(90-1)=8900-180+2 =8722 请采纳,谢谢
9+98×48-49×29-49×10
=9+49×2×48-49×29-49×10
=9+49×(96-29-10)
=9+49×57
=9+2793
=2802