Answer:
Olga's mistake: She did not multiply 
and 
in the beginning
Step-by-step explanation:
The main problem is that when a number is outside of the parentheses on the left side, then you have to multiply that number, in this case , by both numbers in the parentheses. After that, continue solving the problem as you usually would. Hope this helped!
Answer:
40
Step-by-step explanation:
brain-list if correct pls :D
4 books make 1 foot since there are 12 inches in a foot so 4 * 5 is 20
There are 20 books in the stack
It is 16 because 1/4 multiply 1/4 is 1/16 and 1/16 multiply 16 is 1 .But I may be wrong.
Answer: ex-1
Step-by-step explanation:
The -1 is used to show the parabola
