It is given in the question that
Anna buys 12 pens and 20 pencils for a total cost of $16. One pen costs $0.40 more than a pencil.
Let the cost of pencil is $ x .
Therefore cost of pen is

According to the question

Distributing 12 and combining like terms, we will get

Therefore cost of pencil is $0.35 and cost of pen is

Answer:
x is approximately 2.220744
Step-by-step explanation:
This can be simplified a little using properties of logarithms, and then solve it by graphing:

So we use a graphing tool to find the intersection point of the graph of
, and the graph of 
Please see attached image for the graph and solution.
The value of x is approximately 2.220744
<span>idk if this exactly correct but i tried
1 Find and add the lengths of all the polygon's sides
2.Multiply the lengths of equal sides by the number of equal sides.
3 Multiply a regular polygon's side length by the number of sides.
4 Alternatively, use the area and apothegm of the polygon.
</span>
Answer:
-15
Step-by-step explanation:
Answer: negative 10 or -10