简算 51*49-3.51*49+51+3.51=
问题描述：
简算 51*49-3.51*49+51+3.51=
答
=51*(49+1)+3.51*(49+1)
=50*(51+3.51)
=50×54.51
=2725.5
答
51*50-3.51*48=2550-3.51*50+7.02=2557.02-175.5=2381.52打字不算数还累
答
51*49-3.51*49+51+3.51
=51*49+51+2*3.51-3.51*49-3.51
=51*(49+1)-3.51*(49+1)+2*3.51
=51*50-3.51*50+2*3.51
=2550-175.5+7.02
=2381.52