In an A.P ten times of its tenth term is equal to thirty times of its 30 th term .Find its 40th term
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Answered by
35
In AP an= a+(n-1)d
a10 = a+9d
30 th term= a+29d
Given
10 (a+9d)= 30(a+29d)
10a+90d=30a+870d
90d-870d=30a-10a
-780d = 20a
a = -780d/20
a40= a+39d
= (-780d/20)+39d
= (-780d+780d)/20
= 0
ebenezerstephen2017:
This answer is correct but last portion is doubtful
Answered by
13
Answer:In AP an= a+(n-1)d
a10 = a+9d
30 th term= a+29d
Given
10 (a+9d)= 30(a+29d)
10a+90d=30a+870d
90d-870d=30a-10a
-780d = 20a
a = -780d/20
a40= a+39d
= (-780d/20)+39d
= (-780d+780d)/20
= 0
Step-by-step explanation:
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