Mammoth Memory

Three-part inequalities

Three-part inequalities have two symbols in their expressions.

Solving a three part inequality is the same as two part inequalities. As in:

What you do to one side – You must do to the other.

Except now you do it to all three sides.

What you do on one side do on the other



Solve `-4<=2x-1<=5`  

So try to get `x` on its own

Add 1 to all three sides




Divide all 3 sides by 2



Answer: `-1.5`  is less than or equal to `x` and `x` is less than or equal to `3`.

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