The line cuts $X$ and $Y$ axes at the points $A$ and $B$ respectively. The point $(5,6)$ divides the line…

The line cuts $X$ and $Y$ axes at the points $A$ and $B$ respectively. The point $(5,6)$ divides the line segment $\mathrm{AB}$ internally in the ratio $3: 1$, then equation of line is
  1. $2 x+y=16$
  2. $2 x+5 y=40$
  3. $2 x-y=4$
  4. $2 x-5 y=-20$

Solution

Let $A \equiv(a, 0)$ and $B \equiv(0, b)$ Let $P \equiv(5,6)$ and it divides $A B$ in the ratio $3: 1$ $\begin{array}{l} 5=\frac{3 \times 0+1(a)}{3+1} \Rightarrow 5=\frac{a}{4} \Rightarrow a=20 \\ 6=\frac{3 b+1 \times 0}{3+1} \Rightarrow 3 b=24 \Rightarrow b=8 \end{array}$ Thus intercepts on $X$ and $Y$ axes are 20 and 8 respectively. Equation of $\mathrm{AB}$ is $\frac{\mathrm{x}}{20}+\frac{\mathrm{y}}{8}=1$ i.e. $2 \mathrm{x}+5 \mathrm{y}=40$

Asked in: MHT CET 2020 (12 Oct Shift 2)

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