slope algebra
posted by SKipper on .
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?

let B(x,y) be the other point
we know how to get the midpoint
(x  10)/2 = 4
x10 = 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.