Question

the 20th term of an ap is equal to three times its 6th term if its 9th term is 20 . find the ap
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Answer 1

Step-by-step explanation:

9th term= 20

a+8d=20

a+19d=3(a+5d)

a+19d=3a+15d

4d=2a

2d=a

now substitute in a place

(2d)+8d=20

10d=20

now substitute in d place

a+8(2)=20

a+16=20

a=4

44+24+2(2),4+3(2)

4,6,8,10