maths question from algebra 2

Question

four less than half of a number is no less than 23\

 

Answer 1

Let x be the number.  Half the number is x/2.  Four less than half the number is x/2 - 4.  No less than 23 means 23 or greater:

 

(x/2) - 4 ≥ 23

x/2 ≥ 27

x ≥ 54