Answer:
.009 miles/hour
Step-by-step explanation:

This is the method you should take with unit conversions in general, just set up fractions so the units cancel out, like the 7.5 feet cancels out with the feet in the 1/5280 so miles is left on top.
Answer:
You can substitute
4
as
x
in the first equation because
x
and
4
are equal.
2
(
4
)
+
y
=
29
8
+
y
=
29
y
=
21
Step-by-step explanation:
"mono" means 1 or single. In algebra, a monomial is any number that is alone or by itself. For this question, among the choices, the monomial is the number 4. Therefore the answer to this question is letter B. 4.