Answer:
19Sin A - (10/sin A)
Step-by-step explanation:
We want to simplify;
9Sin A + 3cosec A + 10sin A - 13Cosec A
Let's rearrange it for ease of addition;
(9Sin A + 10sin A) + (3cosec A - 13Cosec A)
>> 19Sin A - 10cosec A
Now, from trigonometric ratios, we know that; Cosec A = 1/Sin A
Thus; 10cosec A = 10/sin A
Thus, we now have;
19Sin A - (10/sin A)