SOLUTION: The graph of f passes through (-3,7) and is perpendicular to the line that has an x-intercept of 7 and a y-intercept of -56. The slope intercept form is y=?

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Question 508298: The graph of f passes through (-3,7) and is perpendicular to the line that has an x-intercept of 7 and a y-intercept of -56. The slope intercept form is y=?
Found 2 solutions by oberobic, stanbon:
Answer by oberobic(2304) About Me  (Show Source):
You can put this solution on YOUR website!
First, you have to determine the equation for the line that has an x-intercept of 7 and a y-intercept of -56.
This information defines two points:
(7,0) and (0,-56)
To define the line, you need to determine the slope, m.
m = (0-(-56)) / (7-0)
m = 56/7
m = 8
.
So the line's equation is:
.
y = 8x -56
.
A line perpendicular to it will have slope = -1/8. That defines
.
y = -1/8 + b
.
You can use the required point (-3,7) to find 'b'
.
7 = -1/8(-3) +b
7 = 3/8 + b
b = 6 5/8
.
y = -1/8*x + 6 5/8
or
y = -1/8*x + 53/8
.
In the following graph, the red line is y = 8x-56, the green line is y = -1/8x + 53/8
.
graph%28500%2C500%2C-10%2C10%2C-10%2C10%2C8%2Ax+-56%2C+-1%2F8%2Ax%2B6%2B5%2F8%29

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The graph of f passes through (-3,7) and is perpendicular to the line that has an x-intercept of 7 and a y-intercept of -56.
---
Find slope of line thru (7,0) and (0,-56)
slope = (-56-0)/(0-7) = 8
------
Any line perpendicular to that line must have slope = -1/8
----
Find equation of line with slope = -1/8 and passes thru (-3,7).
Form: y = mx + b
7 = (-1/8)(-3) + b
7 = (3/8) + b
b = (56/8)-(3/8)
b = 53/8
---
Equation:
y = (-1/8)x + (53/8)
=========================
Cheers,
Stan H.
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The slope intercept form is y=?