The advantage is that you can visibly see the difference in the data. Disadvantage of line plots would be that not as appealing.
Answer:

Step-by-step explanation:
When adding rational numbers, if the denominator is the same you simply keep the denominator (bottom of fraction) as it is and apply the operation given to the numerator ( top of fraction )
So we have 
==> remove parenthesis and apply signs

==> simplify numerator by combining like terms

and we are done!
Note:
like terms are terms with the same variable and exponent
An example of like terms are 6x^7 and 3x^7 as they have x as a variable and a power of 7
The like terms being combined here were (6x² and 4x²) and (5 and -2)
Answer: Yes!
Step-by-step explanation:
Yes, graphite is composed of 100%carbon. With this, can we say that graphite is an element or compound of carbon? Compound is composed of two or more elements combined in a substance in definite proportions, in the form of molecules held together by chemical bonds.