Answer:
tan (a+b) = 2.27 or (345/152)
Explanation:
a and b are in the fourth quadrant
sin a = -12/13 tan a = - 12/5 = - 2.4
cos b = 20/29 tan b = - 21/20 =.1.05
tan (a+b) = (tan a + tan b) / (1 - tan a * tan b)
= (-2.4 + - 1.05) / ( 1 - (-2.4)*(-1.05))
= (-3.45) / (-1.52)
= 2.27