we have
[tex]a(n+y)=10y+32[/tex]
Solve for y
[tex]a(n+y)=10y+32\\an+ay=10y+32[/tex]
Group terms that contain the variable y, and move the other terms to the opposite side of the equation
[tex]ay-10y=32-an\\ y(a-10)=32-an[/tex]
Divide by [tex](a-10)[/tex] both sides
[tex]y=\frac{(32-an)}{(a-10)}[/tex]
therefore
the answer is
[tex]y=\frac{(32-an)}{(a-10)}[/tex]