Question

x^3+6x^2+(21x^2+3x-12/x-4)<=3

Answer 1

3x+12x+(42x+3x-12:x-4)<=3
3x+12x+42x+3x-x=12+4+3
49x=19
49:9=2.5

Answer 2

21x^2^x+3x^x-12/x-4^x=21x^3+3x^2-4x-12
22x^3+9x^2-4x-12<=3
22x^3+9x^2-4x-15<=0
Дальше сам группируй)