(2,5)(-1,8)
slope = (8 - 5) / (-1 - 2) = 3/-3 = -1
y - y1 = m(x - x1)
slope(m) = -1
(2,5)...x1 = 2 and y1 = 5
now we sub
y - 5 = -1(x - 2) <==
X = 9 . Basically just divide 12 by 8 and then take that quotient (1.5) and multiply it by 6 in order to receive the product of 9.
Hope this helps! :)
Answer: B. 
Step-by-step explanation:
The notation to express a dependent variable is given by :-
, where Y is depending variable which is dependent upon x ( independent variable).
The given statement : The distance an airplane travels depends on how much time it spends flying.
Here , Independent variable : Time
Dependent variable : Distance
Then , the notation to express distance (dependent variable) the airplane flies in 20 minutes is given by :-

Using the Pythagorean Theorem, we can tell that there is 10 units between the two points.
Answer: 20-4x
Explanation:
20(a number) minus 4 times x