bearing in mind that an absolute value expression is in effect a piece-wise expression, because it has a ± version.
![\bf 3|x|+7=28\implies 3|x|=21\implies |x|=\cfrac{21}{3}\implies |x|=7\implies \begin{cases} +(x)=7\\ -(x)=7 \end{cases} \\\\[-0.35em] ~\dotfill\\\\ +(x)=7\implies \boxed{x=7}~\hfill -x=7\implies \boxed{x=-7}](https://tex.z-dn.net/?f=%20%5Cbf%203%7Cx%7C%2B7%3D28%5Cimplies%203%7Cx%7C%3D21%5Cimplies%20%7Cx%7C%3D%5Ccfrac%7B21%7D%7B3%7D%5Cimplies%20%7Cx%7C%3D7%5Cimplies%20%20%5Cbegin%7Bcases%7D%20%2B%28x%29%3D7%5C%5C%20-%28x%29%3D7%20%5Cend%7Bcases%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20%2B%28x%29%3D7%5Cimplies%20%5Cboxed%7Bx%3D7%7D~%5Chfill%20%20-x%3D7%5Cimplies%20%5Cboxed%7Bx%3D-7%7D%20)
Answer:
x-coordinates of relative extrema = 
x-coordinates of the inflexion points are 0, 1
Step-by-step explanation:

Differentiate with respect to x


Differentiate f'(x) with respect to x

At x =
,

We know that if
then x = a is a point of minima.
So,
is a point of minima.
For inflexion points:
Inflexion points are the points at which f''(x) = 0 or f''(x) is not defined.
So, x-coordinates of the inflexion points are 0, 1
X=27 I think this is correct
Answer:
D is incorrect so ur answer is D
If you're describing a time, then it has to have a unit of time. We have no idea how much gas you're talking about, so second, minute, and hour are all possibilities.