SOLUTION: A line in the (x,y) coordinate plane contains the points P(x,7)and Q(1,1). a) Given that the distance between the points P and Q is 10 units, what is the value of x? b) Use your

Algebra ->  Coordinate-system -> SOLUTION: A line in the (x,y) coordinate plane contains the points P(x,7)and Q(1,1). a) Given that the distance between the points P and Q is 10 units, what is the value of x? b) Use your       Log On


   



Question 1161262: A line in the (x,y) coordinate plane contains the points P(x,7)and Q(1,1).
a) Given that the distance between the points P and Q is 10 units, what is the value of x?
b) Use your answer in (a) to find the midpoint of PQ.

Found 2 solutions by Boreal, MathLover1:
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
That means the sqrt{ (diff in x)^2+ (diff in y)^2}=100
so (x-1)^2+6^2=100
x^2-2x+1+36=100
x^2-2x-63=0
(x-9)(x+7)=0
x=9 or x=-7
The points are (9, 7) and (1, 1) with midpoint (5, 4)
and (-7, 7) and (1, 1) with mid point (-3, 4)

Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

A line in the (x,y) coordinate plane contains the points
P(x,7) and
Q(1,1)
a)
Given that the distance between the points+P and+Q+is 10+units, what is the value of x?
use distance formula:
d=sqrt%28%28x-x%5B1%5D%29%5E2%2B%28y-y%5B1%5D%29%5E2%29....plug in given points and distance
10=sqrt%28%28x-1%29%5E2%2B%287-1%29%5E2%29
10=sqrt%28x%5E2-2x%2B1%2B6%5E2%29
10%5E2=x%5E2-2x%2B1%2B36
100=x%5E2-2x%2B37
0=x%5E2-2x%2B37-100
x%5E2-2x-63=0
%28x+-+9%29+%28x+%2B+7%29+=+0
=> x=9 or x=-7
so, P(9,7) or P(-7,7)

b)
Use your answer in (a) to find the midpoint of PQ.
if P(9,7) and
Q(1,1)
the midpoint ofPQ is
M=(%289%2B1%29%2F2,%287%2B1%29%2F2)=(5,4)
or
if P(-7,7) and
Q(1,1)
M=(%28-7%2B1%29%2F2,%287%2B1%29%2F2)=(-3,4)