Find the equation of the line perpendicular to y = 4x - 5 and passing through (1,-5) .

**Perpendicular lines have slopes which are negative reciprocals.**

**Slope-intercept form is y = mx + b**

m is the slope

b is the y-intercept

m is the slope

b is the y-intercept

In y = 4x - 5,

slope is 4

perpendicular slope is -1/4

point is (1,-5) , slope is -1/4

**y = mx + b**{slope-intercept form}

-5 = (-1/4)(1) + b {substituted point (x,y) and slope into slope-intercept form}

-5 = (-1/4) + b {multiplied}

b = -19/4 {added 1/4 to each side}

y = mx + b {slope-intercept form}

**y = (-1/4)x - (19/4)**{substituted slope and y-intercept into slope-intercept form}

**Ask Algebra House**