The Straight Lines — MATHS STD 11 Science — Question

$\frac{\text{x}}{\text{a}}+\frac{\text{y}}{\text{b}}=1 \ ...(\text{i})$

If (i) passes through point (1, -2) ans has equal intercepts (a = b = k), we get,

$\frac{1}{\text{k}}+\frac{(-2)}{\text{k}}=1$

$\frac{-1}{\text{k}}-\frac{2}{\text{k}}=1$

$1-2 =\text{k}$

$\text{k}=-1$

$\Rightarrow\text{a}=\text{b}=-1$

Putting in (i)

$\frac{\text{x}}{-1}+\frac{\text{y}}{-1}=1$

$\text{x}+\text{y}=-1$