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Grade 11Algebra

  1. prove that 1.2+2.22+3.23+............+100.2100=99.2101+2.

Profile image of abhay singh
9 Years agoGrade 11
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1 Answer

Profile image of moumi roy
9 Years ago
S=1.2+2.22+3.23+............+100.2100
2S=    +1.22+2.23+..........+99.2100+100.2101
SUBSTRACTING,S=100.2101-[2+22....+2100]=100.2101-2(2100-1 )=99.2101+2.