Plz help due tomorrow

In parallelogram abcd the ratio of ab to bcis 5: 3. if the perimeter of abcd is 32 find ab

F(n + 1) = f(n) – 8. if f(1) = 100, what is f(6)?

This is my question~~ ( r ^ 4 - 2r ^ 3 - 23 r ^ 2 - 4r - 32)÷(r+4) ~~ i must use long division to solve it : / i was wondering if anyone world like to solve it. and if so, share step-by-step explanations! you! ❤