Algebra I Recipe: Solving Inequalities With One Variable
By G Redden
- > represents "is greater than"
- < represents "is less than"
- ≥ represents "is greater than or equal to"
- ≤ represents "is less than or equal to"
- Perform the distributive property on each side.
- Combine like terms on each side.
- Add or subtract to get the variable terms on the same side. (Side of the largest coefficient.)
- Add or subtract to move the number term to the opposite side of the variable term.
- Multiply or divide to move the coefficient.
- If you multiply or divide both sides of an inequality by a negative number, the inequality symbol changes directions.
1.
x - 8 < 15
2.
4y + 3 > 7
3.
13 - 7n ≤ -8
4.
3x ≥ 11x + 4
** Make sure the variable is on the LEFT in all solutions.
- A solution with >
- Graph an open circle on the number. (The number is not part of the solution.)
- A darkened bar with an arrow goes to the right of the circle.
- A solution with <
- Graph an open circle on the number. (The number is not part of the solution.)
- A darkened bar with an arrow goes to the left of the circle.
- A solution with ≥
- Graph a solid circle on the number. (The number is part of the solution.)
- A darkened bar with an arrow goes to the right of the circle.
- A solution with ≤
- Graph a solid circle on the number. (The number is part of the solution.)
- A darkened bar with an arrow goes to the left of the circle.
- A solution with a fraction.
- Determine the two integers that the fraction falls between.
- Use these two integers to make one big unit on the number line.
- Divide this unit into the appropriate fractional parts like 1/4's, 1/2's, 1/3's, etc.
- Then graph using Steps 1-4 given above.
- A solution with a decimal.
- Change the decimal to a fraction and graph using Step 5.
5.
2(3x - 2) < 4x + 8
6.
3(4x - 6) ≥ 6(x + 2)
7.
-x + 6 < 2(x - 8)