Answer:
approximately 6.708 feet
Step-by-step explanation:
We use the Pythagorean theorem to solve the problem, using 3 feet and 6 feet as the legs of a right angle triangle. The diagonal of the screen is therefore the "hypotenuse" of this right angle triangle, and can be determined via the formula:

which is approximately 6.708 feet
Answer:
Explanation:
The standard form of an equation is expressed as y = mx+b
m is the slope
Given the equation x - y = 6
Rewrite in standard form;
-y = -x + 6
Multiply through by -1
-(-y) = -(-x) - 6
y = x - 6
Compare with the standard equation
mx = 1x
mx+b
m is the slope
Given
point slope form
y-y1 = m(x-x1)
y-9 = 2(x-1)
change to slope intercept form
y-9 = 2(x-1)
distribute
y-9 = 2x-2
add 9 to each side
y = 2x-2+9
y = 2x+7