UPSC NDA Math Model Paper 9

Given: The line makes equal intercepts on both the axes and passes through the point (4, 7)
Let the x-intercept and y-intercept of the line be a.
As we know that intercept form of a line is given by:

x

a

+

y

b

=1
So, the equation of the line is:

x

a

+

y

b

=1
⇒ x + y = a .......(1)
∵ The line passes through the point (4, 7)
So, the point (4, 7) will satisfy the equation (1)
⇒ 4 + 7 = a ⇒ a = 11
So, the equation of the line is: x + y - 11 = 0
Hence, option B is the correct answer.