根據(jù)有效數(shù)字的運(yùn)算規(guī)則進(jìn)行計(jì)算 (1)7.9936÷0.9967-5.02 (2)0.0325×5.103×60.06÷139.8 (3)(1.276×4.17)+1.7×10-4-(0.0021764×0.0121) (4)pH=1.05,[H+]