If the nth term of an A.P is given by 5n-3 then find 5hr sum of first 10 terms
Answers
Answered by
100
term1=2=a
term2=7
d=5
sum =10/2(2a+(n-1)d
=5(4+9x5)
=245
term2=7
d=5
sum =10/2(2a+(n-1)d
=5(4+9x5)
=245
aishwaryamano:
How do you know a and d????
i have calculated a that is first term by putting n=1 and d by subtracting 2nd term and 1st term
Ok thank you
Answered by
100
Answer: sum of ten terms is 245
Step-by-step explanation:
given, n term is 5n-3
assume n = 1
therefore, a = 2
first term = 2
for second term assume n = 2
n = 5(2)-3
n = 7
d= 7-a =5
therefore, d = 5
sum of 10 term = 10/2 [2(2)+(10-1)5]
= 5[4+45]
= 5[49]
= 245
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