Look up the law of sines, I suggest Khan Academy. It is better if you know how to do it, it is very useful.
52/8 is 6.5 which is 6.5 days 15-6.5 is 8.5 and 8.5 • 8 is 68. 68+52 is the same as 15•8 so i’m pretty sure the answer is 68
Combine like-terms
-2.1x and 4.9x = 2.8x
3.7 and 5 = 8.7
2.8x + 8.7 is your final answer.
Jesus is the lord above all