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