SOLUTION: Give the slope-intercept form of the equation of the line that is perpendicular to –7x + 3y = 14 and contains P(–1, –9). First find the slope of the given equation -7x + 3y = 1

Algebra ->  Equations -> SOLUTION: Give the slope-intercept form of the equation of the line that is perpendicular to –7x + 3y = 14 and contains P(–1, –9). First find the slope of the given equation -7x + 3y = 1      Log On


   



Question 880823: Give the slope-intercept form of the equation of the line that is perpendicular to –7x + 3y = 14 and contains P(–1, –9).
First find the slope of the given equation
-7x + 3y = 14
add 7x on both sides of the equation
3y = 7x+14
Divide everything by 3
3y/3 =7x/3 + 14/3
y =7x/3 + 14/3
Remember y = mx + b where m =slope and (0,b) is the y intercept
Therefore the slope of this equation is 7/3
In order to have an equation that is perpendicular the slope must be the opposite reciprocal therefore the slope of the perpendicular equation is -3/7
Now using the perpendicular slope and points given solve the equation y = mx +B
for b by plugging in the x, y and slope.
y = mx + b
-9 = (-3/7)(-1) + b
-9 = 3/7 + b
subtract 3/7 on both sides
-9 -(3/7) = b
b = 66/7
Now plugging in our perpendicular slope and b into the y = mx + b the equation of the perpendicular line is formed
y = (-3/7)x - 66/7

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