In a certain sequence of numbers, each term after the first is found by doubling and then adding $3$ to the previous term. If the seventh term of the sequence is $125$, what is the first term?

Guest Jun 6, 2019

#1**+2 **

125-3=122

122/2=61

61-3=58

58/2=29

29-3=26

26/2=13

13-3=10

10/2=5

5-3=2

2/2=1

1-3=-2

-2/2=-1

Term 7: 125

Term 6: 61

Term 5: 29

Term 4: 13

Term 3: 5

Term 2: 1

Term 1:-1

The first term is -1

sinclairdragon428 Jun 6, 2019