Question

18. How many terms of the AP -6, -11/2, -5,.......... Are needed to give the sum -25.
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Answer 1

Step-by-step explanation:

a+(n-1)d=-25

-6+n-1×1/2=-25

n-1×1/2=-25+6

n-1/2=-19

n-1=-38

n=-37

verification:

a+(n-1)d=-6+(-37-1)1/2=-6+(-38)/2=-6-19= -25

here d is common difference of given AP

terms of the AP -6, -11/2, -5,.......... Are needed to give the sum -25. are n= -37