Idea 20of 23Builds onPut it back to check
An inequality has many solutions
How can an inequality have more than one answer?
Today you'll discover
- how to test a number
- why the boundary is left out
- how many numbers work
Think firstx + 3 < 7
Which numbers make x + 3 less than 7?
Decide first, then press Next. Test a number by putting it in for x.
The inequality x + 3 < 7 over a number line from 0 to 10. Ticks above 2 and 3, crosses above 4 and 6, with the working for each. Then an open dot at 4, and a thick shaded line from the dot back to 0: every number less than 4.
See the whole ideathe big idea and the key word, in one place
The big idea
An inequality can have many solutions: every number that makes it true.
Compare themEquation x + 3 = 7: one solution, 4. Inequality x + 3 < 7: many solutions, 0, 1, 2 and 3.
Easy to get wrongThe boundary number makes the sides equal. With < or > it is not a solution.
Key word
- inequality
- a statement that one side is less than, or greater than, the other, like x + 3 < 7
Ready to use it?
- Test numbers in an inequality.
- Find all the whole-number solutions.