Implicit differentiation... find dy/dx for tan(x +y)=y

i know that
sec^2(x+y)( dx/dx - dy/dx)= dy/dx
sec^2(x+y)(1- dy/dx)= dy/dx

but what do i do from there?
help please :)

sec²(x + y)(1 + y') = y'

sec²(x + y) + y'sec²(x + y) = y'

sec²(x + y) = y' - y'sec²(x + y)

sec²(x + y) = y'(1 - sec²(x + y))

sec²(x + y)/(1 + sec²(x + y)) = y'

You can leave the above as so or break up the fraction as

1 - 1/sec²(x + y) = y'

Yin