8y²-5y+7 from 2y²+7y+11
[tex]\Longrightarrow[/tex] 2y²+7y+11-(8y²-5y+7)
[tex]\Longrightarrow[/tex] 2y²+7y+11-8y²+5y-7
[tex]\Longrightarrow[/tex] -6y²+12y+4
Answer:
[tex]-6 {y}^{2} + 12y + 4[/tex]
hope this helps...