Please help ;( john is j years old. the product of his younger brother’s and older sister’s ages is j^2-2j-15. how old are john’s brother and sister is terms of john’s age?

Can someone me with this problem . show your work .

Proceed as in example 3 in section 6.1 to rewrite the given expression using a single power series whose general term involves xk. ∞ n(n − 1)cnxn − 2 n = 2 − 4 ∞ ncnxn n = 1 + ∞ cnxn n = 0

What is the absolute value of the complex number -4-sqrt2i