The graph touches, but does not cross, the x-axis at x =
The graph of the function crosses the x-axis at x =
DONE

The true statements are:

Functions are used to represent graphs, ordered pairs, equations and relations

The function is given as;

Next, we plot the graph of function f(x).

From the graph (see attachment), we have the following observations:

Read more about functions and graphs at:

link

i assume that by 5 you mean 5 gallons.

(20)(0.25) = 15

removing 15 gallons reduces the tank from 20 to 5.

because linear equations are a lot simpler than quadratics equations, and linear equations formula is a lot easier to memorize. that's why i think they're harder.