Question 1180320
cos(α - β)= {{{cos(alpha)cos(beta) +sin(alpha)sin(beta)}}}

sin α = 4/5 in quadrant I  cos α = 3/5.

cos β = -5/13 quadrant II means sin β = 12/13.

Plug the values
 (3/5)(-5/13) + (4/5)((12/13)

(-3/13) + (48/85)

(-15+48)/85

33/85