Solve using Determinants and Cramer's Rule?

Question

I was absent and missed the lecture on Cramer's rule and Determinants and have no idea how to start the homework..

The directions and problem are as follows:

Using Cramer's Rule, set this problem up to find "a". Only evaluate the Denominator. When finished with the Denominator, finalize the answer by putting it into the context: a=?/#

6a -4b -5c -2d = -5
-7a +3b + c -3d = -6
2a - 6b + 4c + 9d = 9
4a + 7b - 8c -5d = -2

Thanks in advanced!
(Please show the steps and be as detailed as possible so I can study the process and complete the rest of the problems, thanks!)

Answer 1

actually i have a question

is that 1 big problem or 4 different ones???

Answer 2

that is one big problem haha

Answer 3

I DON'T GET THE MINUSES IN THIS ONE? PLEASE HELP????