Answer:
396
Step-by-step explanation:
Difference of two squares is breaking down numbers into pieces and using the distributive property to solve. The pieces should be in the form (a-b)(c+d).
Write 22 as (20 + 2) and 18 as (20-2).
(20+2)(20-2) = 400 + 40 - 40 - 4 = 400 - 4 = 396
For this case we have that by definition, the equation of a line of the slope-intersection form is given by:

Where:
m: It's the slope
b: It is the cut-off point with the y axis
While the point-slope equation of a line is given by:

Where:
m: It's the slope
It is a point through which the line passes
In this case we have a line through:
(8,4) and (0,2)
Therefore, its slope is:

Its point-slope equation is:

Then, we manipulate the expression to find the equation of the slope-intersection form:

Therefore, the cut-off point with the y-axis is 
ANswer:

Answer:
Somewhere around 6 or 9
Step-by-step explanation: