You can make an cb chart. so to equal -6 you need the numbers -7, 1. so now the equation is ( x - 7 )( x + 1 ). if you want to solve it set it equal to 0 and solve.
The answer is... Five less than C
D is the answer
40050 divided by 3.14 is 12754.77707
Cos(5/12)=65.4
It won't let me do short anwser