|
Question 392244: determine the value of r so that a line through the points with the coordinates (r,4) and (-2,3) has slope 1/4
PLEASE HELP FASTT !! THANKYOUU(:
Found 2 solutions by ewatrrr, spikendb:
Answer by ewatrrr(24785)   (Show Source):
You can put this solution on YOUR website!
Hi
Using the point-slope formula, 
(r,4) and (-2,3)
Applying the point-slope formula***
m = (3-4 ) /( -2-r) = 1/4
 |cross multiplying to solve for r
(-2-r) = 4(3-4)
-2-r = -4
2 = r
CHECKING our Answer***
-1/-4 = 1/4
Answer by spikendb(5)  (Show Source):
You can put this solution on YOUR website! Determine the value of r so that a line through the points with the coordinates (r,4) and (-2,3) has a slope of 1/4
To find r, you first have to plug the coordinates into  .
m = slope
An easier formula to understand is m = y2-y1/x2-x1
You plug in the coordinates to have:
1/4 = 3-4/-2-r
Then you have to solve the formula for r.
1/4 = 3-4/-2-r
You subtract 4 from 3 to get -1
1/4 = -1/-2-r
Next, you multiply both sides of the equation by -2-r/1
By multiplying both sides by -2-r/1, you cancel out the -2-r on the right side, and move it to the left. Only -1 remains on the right side of the equation.
1/4(-2-r) = -1
You multiply both sides of the equation by  , cancelling it out on the left side. By multiplying the -1 on the right side by , you get -4.
You add 2 to both sides of the equation. It cancels it out on the left side, and creates a -2 on the right side.
To isolate the variable, r, you divide both sides of the equation by -1. That gives you the answer
You can check your answer by plugging 2 in for r in the original equation:
1/4 = 3-4/-2-2
1/4 = -1/-4
1/4 = 1/4
The answer to the problem is r = 2.
|
|
|
| |
