Clues for the fourth puzzle

Did you get these expressions for your squares? (The $ is 4x - y, and the * is 15x - 5y.)

42x - 12y. 27x - 7y.
* 12x - 2y.
2x + y x + y
x y
3x + y
$ 8x - y
4x

There's one remaining equation due to the horizontal line below the top left square:

(42x - 12y) + (15x - 5y) = (2x + y) + (x + y)

Therefore, 54x = 19y. You can take x = 19, and y = 54.

See the answer.

Back to Puzzle 3.