Write an equation or inequality for the given situation.

1) Write The quotient of a number and 2 plus 15 is no greater than 7.

2) 20 less than twice a number is less than 10.

3)The difference of 6 and 5 times a number is at
least 21.

4)The product of a number and five, and then
28. increased by 2 is -17.