Answer:
a) 3 b) y = 3x + 11
Explanation:
a)
In order to find the gradient (slope), find the change in y or change in x (rise/run).
-2 - 2 / 7 - (-5)
-2 - 2 / 7 + 5
-4/12 = -1/3
Now that we know the gradient of line AB is -1/3, take the opposite reciprocal of that to find the gradient perpendicular to line AB.
-1/3 ⇒ 3
b)
Take point C's values and the perpendicular gradient found earlier and substitute them into the point-slope form equation.
y - 5 = 3(x - (-2))
y - 5 = 3(x + 2)
y - 5 = 3x + 6
y = 3x + 11