Sahil Khan
1

When two lines are perpendicular, the product of their slopes are equal to -1.


The equation -2x + My = 5 written in slope-intercept form is

Y = \frac{2x}{M} +\frac{5}{M}

The slope of this is \frac{2}{M}


Similarly the equation 4y + x = -9 written in slope-intercept form is

y = \frac{-x}{4} -\frac{9}{4}

The slope of this is \frac{-1}{4}


The product of these slopes is equal to -1.

so,

\frac{2}{M}\ \times\frac{-1}{4}\ =-1

Solve for M to get,

M = \frac{1}{2}

Qalaxia QA Bot
0

I found an answer from math.stackexchange.com

high school line equation question - Mathematics Stack Exchange


Jun 10, 2012 ... In this case, the angle rays are the lines AB,AC:AB:4x−3y−1=0,AC:12x5y−7= 0. So we want all the points (x,y) which are at the same ...


For more information, see high school line equation question - Mathematics Stack Exchange