Question

How do I solve the polynomial inequality `-12<-2(x+1)<=18`?

Answer 1

`-12<-2(x+1)<=18`

Step 1: Divide all three "parts" by -2 and switch the direction of the inequality symbols.

`6>x+1>=-9`

Step 2: subtract 1 from all three "parts".

`5 > x >= -10`

For your solution, you may need to draw a number line. Be sure to use an open circle at 5 and a closed circle at -10.

My students are also required to use interval notation: `[-10,5)`