Since they are not like terms (not the same variables) you cannot simply so you leave it like that.✨ This applies for addition and subtraction only. It’s different with multiplication and division.✨
In the division rule you subtract the exponents<span> when </span>dividing<span> numbers with the same base. </span>One<span> rule for exponents is that exponents add when you have the same base. This works for any number x that you want to plug in except for x = </span>0<span>,because </span>0/0<span> is indeterminate (it is like dividing </span>zero<span> by </span>zero<span>). No matter what number we use when it is raised to the </span>zero power<span> it will always be </span>1.
A function

is periodic if there is some constant

such that

for all

in the domain of

. Then

is the "period" of

.
Example:
If

, then we have

, and so

is periodic with period

.
It gets a bit more complicated for a function like yours. We're looking for

such that

Expanding on the left, you have

and

It follows that the following must be satisfied:

The first two equations are satisfied whenever

, or more generally, when

and

(i.e. any multiple of 4).
The second two are satisfied whenever

, and more generally when

with

(any multiple of 10/7).
It then follows that all four equations will be satisfied whenever the two sets above intersect. This happens when

is any common multiple of 4 and 10/7. The least positive one would be 20, which means the period for your function is 20.
Let's verify:


More generally, it can be shown that

is periodic with period

.
Answer:
126 inches
Step-by-step explanation:
If your drawing is on a 1 : 40 scale, to find the scale's height, divide the ride's height by 40.
420 / 40 = 10.5
So the drawing will be 10.5 feet tall.
To convert 10.5 feet to inches, multiply it by 12.
10.5 * 12 = 126 inches