(12ⁿ-3ⁿ)/(2ⁿ+1)=3ⁿ*(4ⁿ-1)/(2ⁿ+1)=3ⁿ*(2²ⁿ-1)/(2ⁿ+1)=
=3ⁿ*(2ⁿ+1)*(2ⁿ-1)/(2ⁿ+1)=3ⁿ*(2ⁿ-1).
Знаменатель <>0
x(x+4)<>0
x<>0
x<>-4
(3x+2)² - (4-3x)² < 14+37x,9х²+12х+4 - (16 - 24х + 9х²) < 14 + 37x,
9х²+12х+4 - 16 + 24х - 9х² < 14 + 37x,
12х + 24х - 37 x < 14 + 16- 4,
-x <26
x>-26