None of them are correct.
When I factor[ 2cos (square) - 5cos -3], I get (2cos + 1)(cos - 3). 2cos + 1 = 0, 2cos = -1, cos = -0.5,. Using inv cos on calculator, I get 120 degree related angle.
The answer is
2
Explanation
You have to do 2/3 x 3 and you do that by multiplying 2 and 3 (6/6)
Which if you split up is 3/3, 3/3 = 2
30%,
1-5=20%
so 50%-20%= 30%