|
Question 282706: If i needed 2 points to be in Y intercept form, what would the answer be for (-5,2) and (4,1)?
y=mx+b should bt the form. Thanks.
Found 2 solutions by richwmiller, oberobic:
Answer by richwmiller(17219)   (Show Source):
You can put this solution on YOUR website! Your problem makes no sense.
Perhaps you mean
"If I have two points (-5,2) and (4,1), what is an equation in slope intercept form y=mx+b?"
y-y=m(x-x)
2-1=m(4-(-5))
1=m*9
m=1/9
y=mx+b
1=1/9*4+b
1=4/9+b
5/9=b
y=x/9+5/9
Answer by oberobic(2304)  (Show Source):
You can put this solution on YOUR website! y = mx+b is slope-intercept form, where
m = slope
b = y-intercept (defined by x=0)
.
Two points can be used to draw a line.
(-5,2) and (4,1)
.
You also can determine the slope by computing the rise over the run.
rise = change in y = y2 - y1
run = change in x = x2 - x1
.
We can define either point what we want, but we have to keep consistent.
(x1, y1) = (-5, 2)
(x2, y2) = (4, 1)
.
rise = 1-2 = -1
run = 4 -(-5) = 4+5 = 9
.
So,
m = -1/9
.
That means y= -1/9x + b
.
Now we have to compute 'b' to ensure it goes through the points given.
.
We know that when x=4, y=1
Substituting, we find 'b'
.
1 = -1/9*4 + b
1 + 4/9 = b
9/9 + 4/9 = b
13/9 = b
.
So, we now have the equation: y = -1/9x + 13/9
Slope = -1/9
y-intercept = (0, 13/9)
.
The x-intercept occurs where y=0, so we can solve by substitution again.
0 = -1/9x + 13/9
The obvious answer is x=13, so the point is (13,0).
.
Graphing is a good way to check your work.
.
|
|
|
| |
