I assume you mean divide using the conjugate to rationalize the denominator and express the result in standard rectangular form.

Answer:
see explanation
Step-by-step explanation:
A difference of two squares is factored as
a² - b² = (a - b)(a + b)
(g)
1 - 81y²
= 1² - (9y)²
= (1 - 9y)(1 + 9y)
(j)
64x² - 25y²
= (8x)² - (5y)²
= (8x - 5y)(8x + 5y)
Answer:

Where y is the total amount earned, m the amount for each extended warranty and b the fixed cost and x the total amount of TVs
For this case the value of x = 16 since we have 16 Tvs with extended warranties and we can do this:

and solving for b we got:

And then we can conclude that she earns 60 for each TV
Step-by-step explanation:
For this case we can set a linear model like this:

Where y is the total amount earned, m the amount for each extended warranty and b the fixed cost and x the total amount of TVs
For this case the value of x = 16 since we have 16 Tvs with extended warranties and we can do this:

and solving for b we got:

And then we can conclude that she earns 60 for each TV
Step-by-step explanation:
- y=3/4x+(-5)
- -4x+4(3/4x+-5)=-20
-4x+3x-20=-20
-x=-20+20
-x=0
x=0
y=3/4×{0}-5
y=-5