Q:

7y + 4x = 3; (-4, -7) Write the equation in slope intercept form of the line that is perpendicular to the graph of the equation and passes through the given point.

Accepted Solution

A:
Solving the given equation for y results in  y = (-4/7) x + (a constant).

The new line has a slope that is the negative reciprocal of -4/7.  That slope is +7/4.

The new line passes thru (-4, -7).  Thus,

the equation for this new line is  y - (-7) = (7/4)(x - [-7]), or 

y + 7 = (7/4)(x+7)

Let's put this into slope-intercept form:

y = -7 + (7/4)x + (49/4), or        y = (7/4)x + (49/4) - 7,   or

y = (7/4)x + 21/4   (answer in slope-intercept form)