Logic Equations - Brainzilla

How to play

The variables represents unique integers ranging from 1 to the number of variables;
Multiplication is implicit: AB means A times B, or A * B;
Based on the clues (equations and inequations), use the grid to create relations between variables and values:

Click once on a square to mark that value as false;
Click twice to assign the chosen value to the variable;
Click three times to clear the square.

The color of a clue changes after you assign values to all of its variables:

GREEN means that the statement is true;
RED means that the statement is false.

Click on a clue to mark it as used;
The game ends when all values are correctly assigned to the variables.

Tips

Figuring out which variables can't have the lowest or the highest values is a good starting point, e.g, A > B shows that A ≠ 1;
Analyzing the hypothetical equation C + D = 4, we can make the following statements:

C = 1 and D = 3 OR C = 3 and D = 1;
No other variable can be 1 or 3 (see Naked Pairs in our Sudoku Guide).

Another quick tip: A = 2B means that A is even;
Don't be afraid of using pen and paper. Some puzzles might require it.

Logic Equations by size

4x4 »

2C = B
B + D > 4C
4C = D

4A = 3B
2B = 4D

if A + D ≤ 6 then B < 1
if C ≤ 2 then A + B ≤ 4

5x5 »

D + E = B
B + D = A
A + E ≤ 6
C + E = A

C = A + E
E = B + 2
if BE + 3E ≠ B then AA + D > E

C + E = A + B
C + D = B + E
E ≠ 2
A ≠ 5
E ≠ 4

6x6 »

D + E = C + F
B ≠ 2
D ≠ 6
B ≠ 1
B + C = A + F
D ≠ 4
B ≠ 5

4A = 3D
4B = 2D
D = 4C
E > F

A + F = E
B + C = F
C + D = E
C + F = D

7x7 »

2F = A + D
2E = A + C
2E = B + D
2A = E + F
B > E

C = DF
F = G + 2
B + D = A + G

A + F = 10
B + G = 10
B + C = 7
B + F = 9
A + C + E = 10

8x8 »

E + F = C + H
A + G = C + D
F + H = B + E
A ≠ 3
B + F = C + G
G ≠ 2
F ≠ 3
B ≠ 7
G ≠ 8
C ≠ 1
A ≠ 8

D + 9 = A + G
C = BE
A ≠ 8
A = E + 2F + 1
B + G = A

2F = C
A > C
H = 2E
2G = B
B > F
3F = G
D > B

9x9 »

B + C = I
B + H = G
H + I = F
D + G = A
G + I = E
B + D = C

A + I = 5
F + H = 7
E + F = 6
G + I = 6
B + I = 9
A + D + F = 13

4A = 3G
4D = 2H
C > A
H = 4F
3I = B

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