100+99-98+97-96+95-94+93.-8+7-6+5-4+3-2+1
= 100+(99-98)+(97-96)+(95-94)+(93.-8+(7-6)+(5-4)+(3-2)+1
= 100 + 1 +1 +.1+ 1 一共 50个1
= 100 +50
= 150
100+99-98+97-96+95-94+93.-8+7-6+5-4+3-2+1
= 100+(99-98)+(97-96)+(95-94)+(93.-8+(7-6)+(5-4)+(3-2)+1
= 100 + 1 +1 +.1+ 1 一共 50个1
= 100 +50
= 150