#20 four times the sum of number. and 15 is a least20. let x represent the number. : find ball possible values for x

For this case what we have to take into account is the following variable:
 x = represent the unknown number
 We now write the following inequality:
 "four times the sum of number and 15 is at least 20"
 4 (x + 15)> = 20
 We clear the value of x:
 (x + 15)> = 20/4
 (x + 15)> = 5
 x> = 5 - 15
 x> = - 10
 The solution set is:
 [-10, inf)
 
 all possible values for X are:
 [-10, inf)