Question

The equation of the line passing through given pair of points $(2,3)$ and $(4,7)$ given in the form $y=mx+c$ is,

• A. $2x-y-1=0$
• B. $2x+y+1=0$
• C. $2y-x-1=0$
• D. $2y+x-1=0$

Answer 1

Answer: (A)

$2x-y-1=0$

The equation of a line passing through $P(x_1,y_1)$

and $Q(x_2,y_2)$ is $\frac{x-x_1}{x_2-x_1}=\frac{y-y_1}{y_2-y_1}$.

GIven, $P(2,3),Q(4,7)$

Thus, equation of line is:

$\frac{x-2}{4-2}=\frac{y-3}{7-3}$

$4(x-2)=2(y-3)$

$4x-8=2y-6$

$4x=2y+2$

$2x=y+1$

$2x-y-1=0$