Hello from MrBillDoesMath!
Answer:
y^2-5y -4
Discussion:
The problem asks us to find the polynomial, g(y), such that
y^2-5y + 1 - g(y) = 5 => (add g(y) to both sides)
y^2 -5y + 1 - g(y) + g(y) = 5 + g(y) =>
y^2 -5y + 1 + 0 = 5 + g(y) => (as -g(y) + g(y) = 0)
Finally subtract 5 from both sides:
y^2 - 5y + 1 -5 = (5 -5 ) + g(y) =>
y^2-5y -4 = g(y)
Thank you,
MrB