86x98十172用简便方法计算解:根据提取公因式的简便方法,原式=86x98+86x2=86x(98+2)=86x100=8600
74*98用简便方法计算74*98=74*(100-2)=74*100-74*2=7252
176-98=176-(100-2)=176-100+2=76+2=78
86+86X99=86*(1+99)=86*100=8600
86x99+86 =86x(99+1) =86x100 =8600
86*98=86*(100-2)=86*100-86*2=8600-172=8428回答完毕~~有疑问请追问,无疑问请点击【采纳】~祝学习进步~~~\(^o^)/~
45*98=45*(100-2)=45*100-45*2=4500-90=4410
3.86x99 =3.86x(100-1) =3.86x100-3.86 =386-3.86 =382.14
42*98=42*(100-2)=42*100-42*2=4200-84=4116
0.82*98=0.82*(100-2)=0.82*100-0.82*2=82-1.64=80.36.谢谢!