Chapter 7 · Inequalities · page 34 of 68
Solving an inequality
levelAlgebra 1
standard7.EE.B.4b
practiceInequalities
An inequality is solved with the same moves as an equation. The answer is a range, not a single number: x > 3 means every number bigger than 3. The sign stays as it is through adding, subtracting, and multiplying or dividing by a positive.
How to use it
- Undo in reverse order, exactly as for an equation.
- Keep the sign pointing the same way at every step, unless you divide or multiply by a negative.
- Read the answer: ≤ means "at most", ≥ means "at least".
- Check with any number in the range, and with one just outside it.
Example
Where it goes wrong
- Flipping the sign on an ordinary subtraction. Only a negative multiplier or divisor flips it.
- Writing the answer as x = 4 when the question had an inequality sign.