This Problem Set is a part of the Lesson 9, Unit 7, Grade 6. Understand solving an equation or inequality as a process of answering a question: which values from a specified set, if any, make the equation or inequality true? Recognize that inequalities of the form or have infinitely many solutions; represent solutions of such inequalities on number line diagrams. Use substitution to determine whether a given number in a specified set makes an equation or inequality true.