maths Problem -urgent

[Piercy]

Hello

Sorry need homework help - what is going on with these sequences I was never any good at maths - help me help someone else! - Thank you

3, -6, 12, 4, 20, ?

7, 16, 8, 27, 9 ?

2, 7, 26, 101, 400 ?

7, 21, 8, 72, 9 ?

13
40
1595
243

Having said that I could be seeing patterns that aren't there

is the bottom line 729?
7x3=21
8x 3 squared ie 9 is 72
so 9x 9 squared ie 81 = 729

At least that is what I would think - could be completely wrong of course

It's not that easy...

First one I agree, 13
Thereafter, not so sure about patterns - I can see that they could have different answers.

For the second one, I thought the answer was 38

Found the last 2 difficult!

We need a maths teacher!!

Agree with Veg!

Arrgh you see I went
7x 3 is 21
8x3 squared is 72
9 x 3 cubed is 243

How old is your kid?
These seem hard......

I found this for the first pattern but it made my head hurt.

3rd one

x4 then -1 x 4 then -2, x4 then -3 etc, so I make the next term 1611

Ummmm the third one I did first one multiplied by 4 minus increasing numbers equals next one I.e
2x4 is 8 -1 is 7
7x 4 is 28 -2 is 26
26 x 4 is 104 - 3 is 101
101 x 4 is 404 -4 is 400
400x 4 is 1600 -5 is 1595

I cannot find scrap of paper I worked the second one out on

Second could be

number +1 then x2, number add 1 then x3

so
7, 16,
8, 27,
9 ?

which makes the last answer 40 (9+1 then x4)

Oh found second
7x2 plus 2 is 16
8x 3 plus 3 is 24
9x4 plus 4 is 40

7, 16, 8, 27, 9 ?

Alternate numbers: 7, 8, 9, 10 etc
with: 2 cubed, 3 cubed, 4 cubed, 5 cubed

So next number should be 64

8x3 plus 3 is 27 even

Drmum123 is right with the final solution (mine is wrong) have had wine and worked with wrong number.

OP, will you be getting the answers?

Ooh yes I see it grumpy I like it better than mine

I am procrastinating........ I quite like numbers

I agree last pattern could be 243

7 , 21, 8, 72, 9 ?

7 , (7x3), 8 (8x9), 9, (9x27) or think of it as

7 (7x31), 8, (8x 32), 9, (9x 3^3)

3^3 means 3 to the power of 3 if you've not seen this computer notation before.

I currently cannot even find equals on my phone!

I made 2nd one 40.
7
(7x2) +2
16
/2
8
(8x3)+3
27
/3
9
(9x4) +4
40

Next answer would then be 10.

Hello DrMum123 got them correct I believe I had multiple choice answers and DrMum fitted - when do I find out if they are correct in the next couple of weeks - I got the first one 13 but then very quickly lost the will to live!

Thanks for all your help

Was this a competency test for a job application?

1. -6. 12. 4. 20. Ans = 20-7=13

-9. +18. -8. +16. -7.

1. 16. 8. 27. 9

(7x2) +2. 16/2. (8x3) +3. 27/3. (9x4) +4. Ans=40

1. 7. 26. 101. 400

(2x4) -1. (7x4)-2. (26x4)-3. (101x4)-4. (400x4)-5 Ans = 1595

1. 21. 8. 72. 9

7x3. 8x3x3. 9x3x3x3. Ans =243

If this is home work at any level then my kids are screwed asking me for help! Even all your explanations made my brain hurt!