18$-8$book=20pencils that were 10$.
and Brian had 80 cards work: 80÷2= 40+10 new cards=50 cards
20 raise the power 7
Step-by-step explanation:
Which clearly means 20 × itself 7 times
Answer:

Step-by-step explanation:
Recall the formula:

We apply this formula to simplify 
This implies that:



This simplifies to

