For each of the problems 13-20, use partial fraction de- composition to evaluate the integral. 6r - 13 13. (r -3) (xx - 2) 673 + 7x- + 36x + 36 14. 3r + 5x2 - 7x - 22 15. 12-4 20r*- 16x- -124x - 98 16. 4x2 + 25 2-1+6 17. ar + 3r 2c + 20 18. de . (x - 5)(a +1)