Fiding the exact value on sum and difference identities?

Can anyone help me solve these two problem as I am confused on how to them?

1. Find the exact value

cos(x+y) if tan x=5/3 and sin y= 1/3

2.sec(x-y) if csc x=5/3 and tan y=5/12

Can anyone show me how to solve these problems what I am having trouble understanding is what to do with the tan.

For example on number 1 I know you can use sin y to find cos y using square root 1-sin^2 then use cos a cos b+ sin a sin b

But I am confused can anyone show me how to work one of these problems out please?(Crying)