Original equation x = yz / a solve for a
xa = yz
a = yz / x
9(72)= 648 will be your answer to solve this problem but 9 is your distributive property
OK so for this it will be simple
1,000 divided by 200 is 5
so if the plane took 5 hours to do 1,000 miles then the plane was traveling at option A. 200 miles per hour.
Answer: Hello mate!
Clairaut’s Theorem says that if you have a function f(x,y) that have defined and continuous second partial derivates in (ai, bj) ∈ A
for all the elements in A, the, for all the elements on A you get:

This says that is the same taking first a partial derivate with respect to x and then a partial derivate with respect to y, that taking first the partial derivate with respect to y and after that the one with respect to x.
Now our function is u(x,y) = tan (2x + 3y), and want to verify the theorem for this, so lets see the partial derivates of u. For the derivates you could use tables, for example, using that:


and now lets derivate this with respect to y.
using that 

Now if we first derivate by y, we get:

and now we derivate by x:

the mixed partial derivates are equal :)
Answer:
89.6
Step-by-step explanation:
(32°C × 9/5) + 32 = 89.6°F