Question

Find the value of the expression |2x−8| where x=−2.5; 0; 4; 5; 9.5.

Answer 1

The absolute value
`|x|` returns the "positive version" of a number. In other words, if
`x` is already positive, then
`|x|=x`. Otherwise, if
`x` is negative, then the absolute value changes its sign, so that it returns positive:
`|x|=-x`.

So, in this case, we have to plug the required values for
`x` in the expression
`2x-8`. Then, if the result is positive we're ok, otherwise we discard the negative sign.

We have:

`x=-2.5 \implies |2x-8| = |-5-8|=|-13|=13`

`x=0 \implies |2x-8| = |0-8|=|-8|=8`

`x=4 \implies |2x-8| = |8-8|=|0|=0`

`x=5 \implies |2x-8| = |10-8|=|2|=2`

`x=9.5 \implies |2x-8| = |19-8|=|11|=11`