Question

given ab and its midpoint m. the coordinates of a are (-10,-3) and the coordinates of M are (-4,-1)

a. find the coordinates of B.
b. find the slope of am. c. find the slope that is perpendicular
d. find the slope that is parallel
e . write the equation of AM



answers. please check?

a.
b. slope of am is 1/3
c. -3
d. 1/3
e. y=1/3x+b
plug in (-4,-1)
-1=1/3x+-4
x=9?
so y=1/3x+9?

Answer 1

let B(x,y) be the other point
we know how to get the midpoint
(x - 10)/2 = -4
x-10 = -8
x = 2

(y+3)/2 = -1
y+3 = -2
y = -5

coordinates of B are (2,-5)

b) since the slope should be the same for BM , AB, and AM
I will use the original values
slope BM = -4/6 = -2/3
(you will get the same answer for the others, don't know how you got 1/3)

c) the slope of the perp. must be +3/2
d) slope of parallel is -2/3

e) since you slope is wrong, your answer is obviously wrong

y = (-2/3)x + b
(-4,-1) on it
-1 = (-2/3)(-4) + b
-1 = 8/3 + b
b = -11/3

y = (-2/3)x - 11/3

BTW , you subbed the -4 in for the b instead of the x in your solution.