Answer: [tex]-y^4+y^3-8y^2-2y+4[/tex]
***read carefully, the word "from" changes the process of the question a bit
Step-by-step explanation:
[tex]4y^4-2y^3-6y^2-y-1\\-(5y^4-3y^3+2y^2+y-5)\\[/tex]
distribute the negative...
[tex]4y^4-2y^3-6y^2-y-1\\-5y^4+3y^3-2y^2-y+5[/tex]
combine to get
[tex]-y^4+y^3-8y^2-2y+4[/tex]