Question

The number of integer values of m for which the x- coordinate of the point of intersection of the lines 3x+4y=9 and y=mx+1 is also an integer is

(a) 2

(b) 0

(c) 4

(d) 1

Answer 1

Point of intersection

x-coordinate is an integer when 3+4m = ±1 or ±5.

m = -1,-2,-\(\frac{1}2,\frac{1}2\)

Hence there are two values of m.