Answer:
See below.
Step-by-step explanation:
Composition of the functions is sometimes commutative.
Under certain circumstances, they can be the same. However, most of the time, they are not commutative.
For instance, if we have f(x)=x^2 and g(x)=x^3, then:

Most of the time, however, this won't work.
Edit: Added an example.
Try doing opposite fence on the = signs opposite fence example +=-
Answer:
80 ft
Step-by-step explanation:
if 1 = 20 then 20 is width but ? is length
1=20
2=40
3=60
4=80
since 4 in is length then actual length is 80ft
Answer:
She didn't put the sign's in the proper place, it should be ( x + 3 ) ( x - 7 )
Step-by-step explanation:
( x - 3 ) ( x + 7 ) = x² + 7x - 3x - 21 = x² + 4x - 21
( x + 3 ) ( x - 7 ) = x² - 7x + 3x - 21 = x² - 4x - 21