Answer:
7
Step-by-step explanation:
formula for circumference of a circle is
d
7
=
d
d = 7
Answer:
y=3x+4
Step-by-step explanation:
x= the equal amount of books on 3 bookshelves
+4=the other 4 books on the fourth bookshelf
y=the total amount of books
Let

then you will have a^2-12a+36=0 and then you can just factor to find a