2log2 (1-13 / (2x+7)) = 3log2 (2+13 / (x-3)) + 12

2log2 (1 - 13 / (2x+7)) = 3log2 (2 + 13 / (x-3)) + 12

2log2 ((2x+7-13) / (2x+7)) = 3log2 ((2x-6+13) / (x-3)) + 12

2log2 ((2x-6) / (2x+7)) = 3log2 ((2x+7) / (x-3)) + 12

Замена (x-3) / (2x+7) = y

2log2 (2y) = 3log2 (1/y) + 12

2log2 (2y) = - 3log2 (y) + 12

log2 (4y^2) + log2 (y^3) = 12

log2 (4y^2*y^3) = 12

log2 (4y^5) = log2 (2^12)

2^2*y^5 = 2^12

y^5 = 2^10

y = 2^2 = 4

Обратная замена

y = (x-3) / (2x+7) = 4

x - 3 = 4 (2x + 7)

x - 3 = 8x + 28

7x = - 31

x = - 31/7