How do you solve this algebra problem?

Question

http://img165.imageshack.us/img165/397/62738926yo1.png

I already know the answer is D, but I don't understand how to come up with the answer. Please explain.

Answer 1

my answer is A

here's my solution:

20-4/5x>or equal to 16

-4/5x>or equal to 16-20

-4/5x>or equal to -4

then multiply 5 to both sides

-4x>or equal to -20

then divide both sides by -4

x<or equal to 5

*hope this helps

Answer 2

Doing inequalities is like doing equations:

20 - (4/5)x >= 16

20 - 16 >= (4/5)x

4 >= (4/5)x

5 >= x

Answer is A