Ctrl+k

Write and solve simple inequalities

An inequality represents a constraint or comparison between quantities, and the learner translates verbal conditions into one-variable forms such as x+3<10x+3<10 or 2x82x\geq 8, then uses inverse operations to identify every value that satisfies the condition. Solutions are understood as a set, often infinitely many, and represented on a number line with appropriate open or closed endpoints; the scope is simple linear inequalities with accessible whole-number, fraction, or decimal values, not compound or nonlinear inequalities.

Detailed Explanation: Write and solve simple inequalities

An inequality compares two amounts. The symbols mean:

  • << means “less than”
  • >> means “greater than”
  • \leq means “less than or equal to”
  • \geq means “greater than or equal to”

Example

A number plus 3 is less than 10. What numbers could the number be?

Step 1: Choose a variable

Let xx represent the number.

Step 2: Write the inequality

“Plus 3” means add 33, and “is less than 10” means use <10<10:

x+3<10x+3<10

Step 3: Undo the addition

Subtract 33 from both sides:

x+33<103x+3-3<10-3

So,

x<7x<7

Step 4: Describe the solution

The answer is every number less than 7. For example, 66, 00, and 2-2 all work.

On a number line, use an open circle at 77 because 77 is not included, and shade to the left:

 ⁣ ⁣ ⁣ ⁣ ⁣ ⁣ ⁣ ⁣ ⁣ ⁣  7\leftarrow\!\!-\!\!-\!\!-\!\!-\!\!\circ\; \longrightarrow \qquad\quad 7

The solution is:

x<7\boxed{x<7}

Learn by doing: Write and solve simple inequalities

Click a topic below to practice the foundational skills you'll need, learn the steps, or master this skill

Practice with unlimited practice problems

Function Domain - Simple Root of Linear to Domain Definition


    ?