Answer:
9(c^7)
Step-by-step explanation:

c^-4 is equal to 1/(c^4), so 1/(c^(-4)) is c^4.
recall that when it comes to absolute value expressions, once we remove the bars, it turns always to positive, so | -5 |, the bars go poof, and tada!! 5.
Let
be the cost, respectively, of a notebook and a pen. If you buy 2 notebooks and 3 pens (which we know is a cost of $14.50), you spend 
Similarly, if you buy 1 notebook and 2 pens (which we know is a cost of $7.50), you spend 
These two equations form the following system:

Multiply the second equation by 2:

Subtract the first equation from the second:

So, a pen costs 0.5 dollars. Plug this equation in the second equation:

Answer:
yes they are
Step-by-step explanation:
They are both equal because both 2/5 and 20/50 are equal to .4 or 40%