SOLUTION: The slope of the line passing through P(1,4) and Q(x,1) is -3/5. What is the value of x? a. 6 b. 7 c. 9 d. 10

Algebra ->  Linear-equations -> SOLUTION: The slope of the line passing through P(1,4) and Q(x,1) is -3/5. What is the value of x? a. 6 b. 7 c. 9 d. 10       Log On


   

Question 983223: The slope of the line passing through P(1,4) and Q(x,1) is -3/5. What is the value of x?
a. 6
b. 7
c. 9
d. 10
Answer by Edwin McCravy(20059) About Me  (Show Source):
You can put this solution on YOUR website!
Instead of doing your problem for you, I'll do one exactly like it in every
detail so you can do yours yourself using this as a model. The problem I
will do is this

The slope of the line passing through P(2,6) and Q(x,10) is -4/7. What is the value of x?
Use the slope-intercept form:

y-y%5B1%5D=m%28x-x%5B1%5D%29

Wehere x%5B1%5D=2, y%5B1%5D=6, m=-4%2F7

y-6=expr%28-4%2F7%29%28x-2%29

Now we substitute y=10

10-6=expr%28-4%2F7%29%28x-2%29

4=expr%28-4%2F7%29%28x-2%29

Multiply both sides by 7

7%2A4=7%2Aexpr%28-4%2F7%29%28x-2%29

28=cross%287%29%2Aexpr%28-4%2Fcross%287%29%29%28x-2%29

28=-4%28x-2%29

28=-4x%2B8

20=-4x

-5=x

Answer: -5.

Now do yours exactly the same way.

Edwin