用简便算方计算,49×49-51+49×51

问题描述:

用简便算方计算,49×49-51+49×51

49×49-51+49×51
=49×49+49×51-51
=(49+51)x49-51
=100x49-51
=4900-51
=4849

49×49-51+49×51
=49×49+49×51-51
=49×(49+51)-51
=4900-51
=4849