Mencari F

C x F = -2 x (B+E)

2 x F = -2 x 13

2F = -26

F = -13

Mencari A

A / -8 = G^2 - 1 - H

A / -8 = 9 - 1 - 9

A = 8

Mencari D

-F + D = 2 x A - 12/E

13 + D = 2 x 8 - 3

13 + D = 13

D = 0

Board 4

Mencari D