Answer:
The expression would be 5x + 2y = 20
Step-by-step explanation:
We let x be no of hardcover books, and 5x the cost of those books
Same for paperbacks.
then we add them up to 20.
Done!
Answer:
Rewriting 
without an exponent we get 
Step-by-step explanation:
We need to rewrite the following without an exponent.
We need to solve the exponent to find the result.
We know the exponent rule: 
Now using this rule to solve the equation:
So, Rewriting without an exponent we get
Answer:
In the metric system of measurement, the most common units of distance are millimeters, centimeters, meters, and kilometers.
I think it is right ...
Think:
7:55 a.m. is 5 minutes (5/60 hrs) before 8 a.m.;
from 8 to noon it's 4 hours, and from noon to 2:40 p.m. is 2 2/3 hours.
Thus, you're in school 5/60 hrs + 4 hrs + 2 2/3 hrs, or
6 2/3 hrs + 5/60 hrs, or 6 40/60 hrs + 5/60 hrs, or
6 45/60 hrs, or 6 3/4 hrs.
Of course there are other ways in which you could do this problem:
4 hrs 5 min plus 2 hrs 40 min comes out to 6 hrs 45 min, or 6 3/4 hrs.
