Re: In the xy plane line m has the equation 4x + y = k. Line n

You can approach by calculating slopes of both lines m and n.

As we know both m and n lines are perpendicular; slope m* slope n= -1

slope of m= -4 since 4x=y+k =>(Y=mx+c), where m is slope

now calculate slope of n. as we know line passes through origin (0,0) and (r, r+1)

slope = (y2-y1)/(x2-x1) => (r+1-0)/(r-0) => (r+1)/r

lines are perpendicular; thus we can multiply both slopes

(r+1)/r*-4=-1 gives r= -4/3

Hence Ans is A.

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