Question

The equation of the line through (1, 2), which makes equal intercepts on the axes, is

(a) x + y = 1 

(b) x + y = 2 

(c) x + y = 4 

(d) x + y = 3

Answer 1

Correct option is: (d) x + y = 3

Let the equation of required line be x/a + y/b = 1……..(i)

Since the line makes equal intercepts on the axes, a = b

x/a + y/a = 1

∴ x + y = a ……(ii) 

But, equation (ii) passes through (1, 2). 1 + 2 = a 

∴ a = 3 

Substituting a = 3 in equation (ii), we get x + y = 3