lg5 X lg20 - lg2 X lg50 - lg25

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/28 12:40:32
lg5 X lg20 - lg2 X lg50 - lg25
x)I7UPI72PQ`)cjTOH~ Q<ۼYK? I745$ @dQ1@S(` 02hZ 7P @34@0/.H̳y5 e

lg5 X lg20 - lg2 X lg50 - lg25
lg5 X lg20 - lg2 X lg50 - lg25

lg5 X lg20 - lg2 X lg50 - lg25
注意lg2+lg5=lg10=1
lg5 X lg20 - lg2 X lg50 - lg25
  = lg5 X (lg2+lg10)-lg2 X (lg5+lg10)-2lg5
  = lg5 X lg2+lg5-lg2 X lg5-lg2-2lg5
  =-lg5-lg2
  =-lg10
  =-1