write the sum of first 40 terms of the sequence -5,-8,-11,-14.....
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Answer:
a=-5. , d = -11-(-8)=-11+8= -3, s40=??
Step-by-step explanation:
since , Sn = n/2[2a+(n-1)d]
therefore , S40 = 40/2 [2×-5+(40-1)-3]
= 20 [-10 -117]
= 20×-127
= -2540
sorry , for the silly mistake ,hope it helps
if this ans is wrong pls notify me.
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