Question

6 more than five times a number x is at least 21

Answer 1

To answer this inequation, you have to write the following: 
6 + 5x => 21 (we write the 6 more than five times a number x is at least 21)
5x => 21 - 6 (transfer the 6)
5x => 15 (calculate this)
x => 3 (here is the answer)

x => 3

Answer 2

5x+6=21
5×3+6=21
if it can be any number more then 21 it could also be
5x+6=26
5×4+6=26