Puzzle 1

Two lower numbers need to be subtracted from upper number which will result in middle digit. 
Onderste twee cijfers - bovenste cijfer is het middelste cijfer.

Conclusion:
7 + 9 - 4 = 12
1 + 4 – 1 = 4
6 + 5 – 2 = 9

Answer = 9

Puzzle 2

Add up all numbers in the same quadrant from left to right. In the third triangle you can see the answer. 
Je moet alle cijfers in hetzelfde kwadrant van links naar recht bij elkaar optellen. In de derde driehoek zie je het antwoord.

Conclusion:
4 + 5 = 9
5 + 2 = 7
9 + 8 = 17
3 + 7 = 10

Answer = 10