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

The mean is like the average. you would add up all the numbers and divide by the amount of numbers there are. in this case, add them all up and divide by 6 because there are 6 different numbers. this will give you your answer
His mistake is he didn't make 6/10 to 60/100 he added them without changing the 6/10
Answer:
hello
bring the side of the first part of the triangle then you can to bring the (x) of the second traingle