Question

7th term of an AP is 40. if its common difference is 3 its first term is_____​

Answer 1

Answer:

solved your question by this example

Answer 2

Answer:

40th term---40-3=37

39th term----37-3=34

38th term --34-3=31

37------31-3=28

26---28-3=25

35---25-3=22

34---22-3=19

33----19-3=16

32---16-3=13

31----13-3=10

30---10-3=7

29----7-3=4

28----4-3=1

27th term -----1-(-3)=4

26th term -----4-(-3)=7

25th term------- 7-(-3)=10

go till first term

hope it helps

or can also use the second method