▲ ▲ ▲ Math contest [Solution]

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Heyo, Steemians!
As you remember, I've launched math contest here. And the deadline for your answers was yesterday at 23:59.

Unfortunately, nobody gave the correct answer for my task. And nobody explained the logic of their attempts.
So, I probably need to do two things:

-Make contests easier :D
-Explain the solution

Let's do the second firstly. Okay, the task was:

p1_9.png

So, the main logic was to see a row dependency here.
Besides, you should to see that last number in every row is special (its orange instead of blue).
Okay, now we get this:

3,4,5->6
1,4,2->3
7,4,8->9
8,x,3->9

Then, we should try to think up a mapping between (a,b,c) -> d (dependency in other words).
The form of figures helps up - it's easy to check that we should evaluate the sums of powers (the value of power is value of figure vertices):
111312312.png
After we should just check our assumption.
Now we had simple cubic equation to determine x:
8^4 + x^3 + 3^4 = 9^5
After some arithmetic we get:
x^3 = 54872
Only one root x = 38.
So the answer was ... 38 :D May be way too tricky, but I'd give 2 dollars without any regret for this answer.
Thanks for your attention and for participation! Follow ideamaker@ideamaker for more easier contests :D

▲ ▲ ▲ Math contest [Solution] | Ecency