I do not agree with the statement.
The "substance" can be a compound. It's "pure"
as long as there's nothing else in it but its name.
'Pure' water is 100% H₂O with nothing else in it.
'Pure' table salt is 100% NaCl with nothing else in it.
'Pure' carbon dioxide is 100% CO₂ with nothing else in it.
These example substances are all compounds, not elements.
Answer: 
<u>Explanation:</u>
A linear equation is of the form: y = mx + b where
- m is the slope
- b is the y-intercept (where it crosses the y-axis)
x + 4y = 16
4y = -x + 16


The y-intercept (b) = 4
Next, find the slope given point (4, 5) and b = 4

Without being provided a list of items, I would have to generally say that everything around you is matter. There are a few exceptions to this list, but a general rule of thumb is anything you can touch, taste, smell or hold would be considered matter. Sound, light, time (Dr. Who may disagree) and heat would be considered non-matter items.
Always stop as soon as you can at a safe place and shut the engine off when the warning/gauge light goes on in a vehicle.