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The sum of first 6 terms of an arithmetic sequence is 99. Its 6 term is 39a) What is the sum of its 3nd and 4th terms?b) Which is the 3'd term?c) Write the sequence. |
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Answer» S6=3(2a+5d)=992a+5d=336th term=a+5d=392a+5d-a-5d=33-39a=-6-12+5d=33 so d=93rd term+4th term=a+2d+a+3d=-12+45=333rd term=a+2d=-6+18=12sequence=-6,3,12,21,30,39,... |
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