What is the Pattern for Finding the Missing Number in a Sequence?

[member 428835]

Homework Statement

what's the missing number

Relevant Equations

nothing comes to mind

I have no idea. I've tried squaring, cubing, summing numbers but can't make sense of anything. Literally no clue how to even approach this aside from randomly adding and subtracting numbers, their squares and cubes, but nothing makes sense. Any ideas?

 

[fresh_42]

1360

 

[member 428835]

1360

But how? And how would I even go about doing this?

 

[anuttarasammyak]

28=4*7=(1+3)*(5+2)

 

[member 428835]

28=4*7=(1+3)*(5+2)

How on Earth did you know to do this? Just random guessing? What all did you check prior to this?

 

[Mark44]

Just random guessing?

Not really. The very first thing I tried, for all of about 5 seconds, was addition, which seemed a dead end. Then I noticed that in the first problem 5 and 2 added to 7, and 3 and 1 added to 4 -- 4 * 7 = 28. The pattern was the same for the second problem.

 

[member 428835]

Not really. The very first thing I tried, for all of about 5 seconds, was addition, which seemed a dead end. Then I noticed that in the first problem 5 and 2 added to 7, and 3 and 1 added to 4 -- 4 * 7 = 28. The pattern was the same for the second problem.

Makes sense, thanks.