Rule 1: Multiply by 2 then add 1 starting
( n x 2 +1) => 2n + 1
n is the position of our terms, so I substitute 1 because you're told to start from 1 which becomes our first term
2n + 1
2 x 1 + 1 =3
2 x 2 + 1 = 5
2 x 3 + 1 = 7
2 x 4 + 1 = 9
3,5,7,9....
(you can clearly see the sequence increasing by 2 each time, not following Multiply by 2 then add 1)
However, if we were to do add one each time, you'll add one to your pervious answer. So, this time I'll substitute the pervious answer
2 x 1 + 1 =3
2 x 3 + 1 = 7
2 x 7 + 1 = 15
2 x 15 + 1 = 31
3,7,15,31....
(from 3 to 7, you clearly see its multiplied by 2, then +1 & that's our sequence, this method apply to the second rule too of using previous)
Rule 2: Divide by 2 then add 4
(n ÷ 2 + 4) => n/2 + 4
n/2 + 4
(starting from 40.)
40/2 + 4 = 24
24/2 + 4 = 16
16/2 + 4 = 12
12/2 + 4 = 10
24,16,12,10.....
Answer: (started off with the number it asked of)
R 1 -
1,3,7,15,31....
(1 x 2 +1 does give 3)
R 2 -
40, 24,16,12,10.....
(40÷2 = 20, then + 4, gives 24)
Hope this helps!
