800^2 - 2*800*798 + 798^2 = (800-798)^2 = 2^2 = 4
2014^2 - 196 = 2014^2 - 14^2 = (2014+14)(2014-14) = 2028*2000 = 4056000
利用公式进行简便计算第一题800-1600*798+798^2第二题2014^2-196
800^2 - 2*800*798 + 798^2 = (800-798)^2 = 2^2 = 4
2014^2 - 196 = 2014^2 - 14^2 = (2014+14)(2014-14) = 2028*2000 = 4056000